Tunerpro RT $4F connection problems

[duecepipes22]

Hi Guys, I'm another newbie to this but working my way up the steep learning curve thanks to your help! I have a '91 350 TBI with a 1228747 comp. I've data logged with WinALDL using the 7747 because it doesn't have the 8747 option on it. While doing logging with WinALDL I found that I'm running pig rich with all my BLMs between 100 and 115. I had a custom chip burned for it a while back but when he burned it, I had a bad TPS (the voltage started dropping after half throttle) and a weak fuel pump (the pressure dropped from 12 psi to 9 under a load.) I also found from datalogging that I have a high knock count at 800 RPMs and the MAP at 65. Is this likely a false knock and is it retarding my timing? I don't know what my base timing is at but does the truck run the base timing at idle or only until it goes into closed loop? When he burned it, he did some soldering so I'm assuming I have the extra 2 pins now to use an EEPROM chip?? Do I just need to look on my chip for a number to see what I have?

ANYWAY, I tried using the $4F mask files and other files found on here (thanks for your work on them) but I can't connect to tunerproRT with them. I am able to connect with the $42 mask files though. My other question is, when I am using TunerproRT I need to put the 10K resister between pins A and B on my ALDL cable but when I do it, my idle increases and stays about 500 higher. However, if I use WinALDL if I have the resister in that position, it doesn't read the BLMs, I have to have it in the "normal" position for it to read. Last question, does anyone have a recommendation, given what I have, for what to use to burn chips once I get to that point?

Sorry this is so long, but I'm lost and have a lot of questions! Thanks in advance!

[EagleMark]

We had those $4F xdf and adx files working so I don't know what the issue is? No 10K... that will put it in ALDL mode. It's almost indentical to $42, one item differant.

Until you read the bin file on chip only your tuner and God knows what's there?

Base timing is what you set distributor at and then set it in bin, until you know what's in bin you should run stock 0 degrees with timing light and timing bypass wire disconnected. When connected it is computer controlled to timing table.

For chips and burner and adapter look at Moates.net

[duecepipes22]

Thanks for the reply and all of your work on here! So can I just use the $42 files and everything should work fine? If I don't use the 10K, it won't connect to tunerpro or atleast I couldn't get it to.

Do I need the chip burner to read the bin file on the chip or can I read it through tunerpro?

I'll check my base timing as soon as I can get my hands on a timing light. The guy that burned my current chip never bothered to find out what my base timing was. He used his snap on scanner tool so I think he just adjusted my fuel tables and advanced my timing a little. In fact, like I said, he managed to burn it without realizing that my TPS was completely shot.

I've been looking at the stuff on Moates but wasn't sure if there was something that you would recommend? Do I still need an adapter if the guy that tuned it already was doing some soldering on the ecm? He said he had to add a couple of pins to use a newer style chip... thats all I know. Thanks again!

[EagleMark]

This topic has come up recently about 10k for 160 Baud ECMs. Not sure about all 160 Baud ECMs but I just went and did some testing on my 1990 Chevy Suburban 1227747 $42 and 10k is not needed to start data flowing with a cable or the AutoProm. AutoProm in AutoProm Mode and Pass Through mode work fine with no 10k. Cable works fine with no 10k. Using 10k on AutoProm or cable puts ECM in ALDL mode which increases idle, spark and who knows what else making tuning and accurate data logging impossible.

Also tried the $4F-1228747-LD-V1.1.adx‎ and it worked fine with no 10k and 10k put it in ALDL mode. There is a Light Duty (LD) and a Heavy Duty (HD) adx file for this ECM.

Looked at ALDL files and no indication of 10k needed to start data flow.

Using either of those ALDL files or the $42 file I doubt you would ever notice the difference?
$42 = #6 HIGH BATTERY VOLTAGE
$4F LD = #6 1ST TIME IDLE FLAG 0 = FIRST TIME
$4F HD = #6 HIGH BATTERY VOLTAGE-DISABLE MCU SOLENOID DISCREETS

If you can not get data to flow with your 1227787 ECM and the $4F file above then use 10k to start data then disconnect and let us know how it worked?

You do need a burner to read the chip, if you get the Burn 2 or AutoProm from Moates they are built into TunerPro.

If you have a modified chip installed in your ECM then chances are it can be plugged into a burner and erased and re programmed.

My choice is the AutoProm. It is a chip burner, cable for data logging and an Emulator in one package. The Emulator lets you tune your bin file while open in TunerPro Real Time. When done burn a final chip. Since you already have a cable, if you only want to make small changes one at a time, burn chip and test/data log then a Burn 2 would do. But if you wanted to Emulate later then you would need an Ostrich as well. AutoProm is all three, cable, Burn 2 and Ostrich.

[RobertISaar]

you know what would possibly be a good project? taking any ECM that requires a 10K for whatever reason, removing the requirement from the algorithm and just having it stream full speed at all times.

[EagleMark]

I guess that would work. Don't know why it's there in the first place? Maybe to save processor speed?

Don't even know what ECMs need it?

[RobertISaar]

AFAIK, not that many... even in the C3 era, it seems not that many need it to start, let alone sustain, a datastream.

the 1227165... i can see that one benefitting, but it also has all kinds of other issues, so IDK.

[duecepipes22]

Thanks again for your help guys! Mark, I'll give that a try tomorrow and let you know how it goes. My truck is a heavy 3/4 ton so I used the HD adx, maybe I should have used the LD? I'll try some stuff tomorrow and report back.

Whats the purpose of ALDL mode if you can't data log with it?

[EagleMark]

Whats the purpose of ALDL mode if you can't data log with it?It's for diagnostics but I don't know what to use it for? I can diagnose anything without, so maybe I need to learn a new trick?

[1project2many]

ALDL Mode... had to dig out the old books on that one since it's been so many years since I had to play with it.

"ALDL (10K or Special) Mode (not used on all engines)
In this mode, all information incorporated into a specific engine and ecm is obtainable. However, in this mode the system operating characteristics are modified as follows.
... Closed loop timers are bypassed
... EST (spark) is advanced
... IAC will will control engine idle to 1000 RPM +/- 50 rpm
... On some engines canister purge will be enabled
... P/N restrict functions will be disabled"

As I remember it, we used ALDL mode in carbureted applications. You would do neat tricks back in the day like speed warmup along or search for vacuum leaks or force closed loop right away to start adjusting the computerized carburetor's rich and lean stop. Or you would crank the engine rpm up to 2500 so the exhaust manifolds would get red hot and burn the carbon off the O2 sensor and the plug tips. Remember that in those days we still diagnosed much of the car with a voltmeter and common sense. ALDL data on a CCC car was extremely slow and in road test mode it was sometimes limited or not available.

Also, for a while you could force ALDL mode and get through sniffer emissions tests. Eventually the states caught on and would flag you if idle was too high. So you'd run it in ALDL mode at 2500 to get the cat and exhaust super hot then pull the connector and run the sniffer test right away.

You can also put a 3.9K resistor across A and B to force the ecm to run in backup fuel if you're so inclined.

Why the OP needs the 10k resistor is a mystery. I'd suspect the logger software/hardware combo, not the ecm, is at fault.

[EagleMark]

Well the only trick I think this would be helpful for would be dead of winter warm ups... or if you need data from a $6E Camaro... I can't beleive all that 10K resistors in cables have only caused me trouble and I have yet to need one!

[duecepipes22]

Well I reinstalled tunerpro and was able to connect with the $42 files without using the resistor however when I looked at my TPS% it read 28% at .55v so I think either there is a glitch in the file or the two are not completely compatible? I was still unable to connect with the $4f but I'm going to keep messing around with it. Any other suggestions?

[EagleMark]

Don't worry about the TPS % reading as it is just a conversion from voltage. Unless you installed the hack which would be accurate.

Post the $4F adx file you have, no reason for it not to work, it is a simple 160 Baud conection same as $42.

[duecepipes22]

This is the file that I downloaded from here. I hope the attachment works.

[EagleMark]

It had one mistake, but so did the LD one I used yesterday? You can try this one. Like mentioned above for data logging only one byte of info differant the $42 and it's not even something you need. But $42 has lots of stuff specific to hacks from XDF and I have no idea if they would work on the 1227787 $4F...

I wonder if it has to do with your hooking up with $42 then changing to $4F without disconnecting, changing file reconnecting?

[duecepipes22]

I'll give those a try tomorrow. When I used the $42 mask, I also used its XDF and when I used the $4F mask I used the $4F XDF. I think when I tried using the $4f this morning, I tried it before connecting with the $42 but I'll try again tomorrow to make sure.

On a somewhat unrelated noted, I've been chasing a sputtering idle for some time now and today I was working on adjusting my minimum idle air (I think my chip has the idle set extremely low because even with the TB adjusted to 550 RPMs, my IAC count is zero). I still couldn't get the idle to smooth out once it goes into closed loop (idles fine at the same RPMs while in open loop). I was once again checking for vacuum leaks and replaced the gaskets above and below my TB spacer which may have helped a little but when I sprayed lighter fluid by the base of my EGR the idle went way up. I had swapped out the EGR awhile back with a spare one I had without changed that gasket. Autozone didn't have the gasket in stock but hopefully tomorrow I will solve a 2 year idle mystery!

[EagleMark]

I was once again checking for vacuum leaks and replaced the gaskets above and below my TB spacer which may have helped a little but when I sprayed lighter fluid by the base of my EGR the idle went way up. Vacuum leak!!!!

Once you fix that you will probably get some IAC counts and a stable CL idle.

You don't even need an XDF to data log, but do for data tracing. Just because the ALDL data is so close does not mean the bin file is same format so do not use the $42 xdf to make changes in bin file.

[duecepipes22]

Well I didn't get a chance to try connecting to TP with that file but I did change out my EGR gasket. It appears that its no longer leaking, but my idle still stumbles! Is there any chance that I need to reset my ECM so it can relearn to run without the leak?

[EagleMark]

Really should not be necessary, but without data we really don't know what's happening or if any codes are set, if there's another issue?

[duecepipes22]

I didn't get a chance to work on the tunerpro stuff because I've been focusing on the idle issue, but here is an update: Checked my timing today, it was almost right on 0* but I adjusted it spot on 0. I noticed that when the ecm wire wasn't hooked up, it idled perfectly but once I plugged it in, it started idling a little rough and like I said before, if its in open loop at 600 RPMs, it runs smooth, if its in closed loop at 600 it idles rough. It was hard to tell but it looked like timing was advanced about 16* at idle in closed loop but it kind of looked like the timing was searching the whole time. In the past when I data logged with WinALDL I had knock at idle... any thoughts? My next step will be to try to connect the $4F with tunerpro and try to data log.

[RobertISaar]

the timing "searching" is normal, it's part of the idle stabilization routine, in addition to IAC movement.

[EagleMark]

0 wire disconnected and 16 connected is also normal. Also have to clear code 42 after doing this.

What is your IAC reading now, warmed up closed loop idle?

Stock motor?

How many miles on motor?

How many miles on O2 sensor?

Any codes?

Can you get a data log to post yet?

Mechanical things like plugs, cap and rotors on these are notorious for being disenigrated and still run, but have issues.

Fuel pressure? Fuel filter...

That said there are some changes that can be made to bin file to help more stable idle.

[duecepipes22]

0 wire disconnected and 16 connected is also normal. Also have to clear code 42 after doing this.

What is your IAC reading now, warmed up closed loop idle?

Stock motor?

How many miles on motor?

How many miles on O2 sensor?

Any codes?

Can you get a data log to post yet?

Mechanical things like plugs, cap and rotors on these are notorious for being disenigrated and still run, but have issues.

Fuel pressure? Fuel filter...

That said there are some changes that can be made to bin file to help more stable idle.

I have some of these answers off the top of my head, I'll have to connect tunerpro tomorrow to get the rest.... The motor, plugs, cap and rotor have 11,000 miles on them with a mild RV cam. O2 sensor has probably about 5,000 on it. New IAC and CTS. Brand new delphi vortec fuel pump, fuel filter has about 5,000 miles on it. Truck itself has 262,000 miles on it. My pressure was at 12.5 but I dropped it to 11 because it was running so rich. I'm going to set it at 13 before I do any tuning. No codes. The rest I don't have answers to yet.....

I'm going to try the new ADX you posted on here tomorrow and will do some data logging if it works and post the results. Thanks again guys!

[duecepipes22]

I got connected! Here is my data log from this morning. This was taken right after I had reset the ECM so I hope that doesn't mess up the data.

[EagleMark]

Looks to be runnign pretty good! Except idle is very rich... this could be the cam.

What bin/BCC is in truck? Can you burn chips yet?

[duecepipes22]

Looks to be runnign pretty good! Except idle is very rich... this could be the cam.

What bin/BCC is in truck? Can you burn chips yet?

It did seem to be running pretty good today, as they always do when the mechanic is watching. I think pulling some fuel pressure helped because it was running rich all over. I'd like to be running higher than 11 psi again. I am trying to order the Burn2 so I can burn but I can't figure out how to check out on the moates site. I type in my billing info and I can't go to the next step on the checkout process because there is no button to do so.
Not sure on the truck bin... how would I figure that out?

[EagleMark]

Call Moates and tell them you have an issue, they just redid their website... there was also a good deal on Burn 2 in for sale section here.

Look at ECM for numbers and letters. Should be like 1228747 and a four letter BCC like ADSU. Or open cover and read BCC off chip.

Problem with lowering pressure, if it is accurate, is it may fix bottom end rich and leave you with not enough fuel WOT high RPM! Then you start all over with more pressure... My gauge is accurate and a stock to relatively stock motor just runs good at 13 psi, lower = worser... if your using a cheap gauge and have between 12 and 14 your ready to tune.

Any cam change from stock will drop idle MAP, which adds fuel. Your log is showing exactly that. Although off idle up looks very good.

Looking at your log I noticed some MAP readings... where do you live? Elevation? Temps that day? Stock air filter setup?

[duecepipes22]

My ECM is the 1228747. Other numbers on it are 86AKWL and K391720208.

I plan on bumping my fuel pressure back up to 13 tomorrow when I install a set of injectors that I sent in to have flow matched.

I have no IAC counts at idle which I would assume is because I adjusted my throttle blades to bring up the idle. I'm thinking that the idle in my bin is pretty low.

Whats going on with the MAP readings? I live in Minnesota. I data logged this morning when it was probably about 60 degrees. I'm not sure about the elevation but its not low or high, an inbetweener if you will. I have an open element k&n filter right now with one of those hypertech powerchargers. I've been working on a carbon fiber cowl hood that should be going on soon which will hopefully help the burning hot air issue. I probably should have also added that I have long tube headers with true duals and an H pipe so its pretty free flowing on the exhaust end.

Is there any indication of bad sensors anywhere? My MAP has 262,000 miles on it as do the distributor and coil. Basically everything else has been replaced.

[EagleMark]

AKWL is the bin number/BCC code.
http://www.gearhead-efi.com/BCCFind/result.shtml?BCC=AKWL

I didn't see any issues, just you got into 100 kpa MAP a couple times and that does normally not happen with stock air intake. Usually 90...

Have to get those throttle blades closed a little to let IAC control idle. 20 is good but usually need a restart after each 1/4 turn, then wait for closed loop, rev engine, let idle and see where they are. Rinse and repeat!

When your done look to see where TPS voltage is.

262k is a lot of miles but MAP sensors don't seem to care... pickup coils in distributor and distributor shafts do! Also throttle shaft on TB if not replaced could be worn and leak some vacuum.

[duecepipes22]

Is it a good thing that I got past 100 kpa? Does it say anything about how I'm flowing air?

When you say I need a restart after each 1/4 turn do you mean I need to reset the computer once everything is adjusted and idling?

I don't doubt that the throttle shaft is worn because I can feel a slight wiggle to it but I never considered that they could be leaking vacuum because of it... shoot. I just tried swapping the TB off a '91 burb that had no play in the throttle shafts but one of the vacuum lines is different on it. What kind of a job is it to replace shaft bushings? I know one place I talked to about flow matched injectors said they would do a complete rebuild for $300 but I don't wasn't sure if I could do it myself.

I also noticed while data logging that I was throwing a "high battery voltage" code. Is that a problem?

[EagleMark]

is it a good thing that i got past 100 kpa? Does it say anything about how i'm flowing air? no data for that but i beleive you are going to see nothing but improvements and big ones if you learn to tweak this right!

when you say i need a restart after each 1/4 turn do you mean i need to reset the computer once everything is adjusted and idling? yes!

i don't doubt that the throttle shaft is worn because i can feel a slight wiggle to it but i never considered that they could be leaking vacuum because of it... Shoot. I just tried swapping the tb off a '91 burb that had no play in the throttle shafts but one of the vacuum lines is different on it. What kind of a job is it to replace shaft bushings? I know one place i talked to about flow matched injectors said they would do a complete rebuild for $300 but i don't wasn't sure if i could do it myself. way cheaper options available, even find a low mile used, my suburban is tight at 125k, you may not even need that vacuum line?

i also noticed while data logging that i was throwing a "high battery voltage" code. Is that a problem? probably not as that was the only thing differant between the 3 files, if you used the hd you probably need the ld hth!

[duecepipes22]

Sounds good. So you think there is still some power left on the table?

I actually think the vacuum line was for my MAP. I'm not looking at it right now, but I just remember thinking that there was no way I wanted to mess with switching it around. I'll have to check the local bone yards.

Just so I get this right and make it easier on you, I'm going to type it all out and you can tell me if this is right. To adjust minimum air, I turn ignition on, connect pins A and B, unplug the IAC, start engine, turn down screw 1/4 turn, shut off engine, plug in IAC, start engine, make sure its in closed loop, rev engine, let it idle, shut off, reset ECM, repeat whole process.

I'll try the LD file tomorrow! As always, THANK YOU!

[EagleMark]

Vacuum for MAP is always there and center rear of TBI, between fuel lines.

IAC = no... your combining the proper way and my shortcut and got it all wrong!

Proper way is engine toatllly warmed up. Turn off, cross A and B turn key on and walk around to pull plug off IAC, it will be closed by the time you get there. Remove A and B, start engine and wait for Closed Loop, adjust idle to 100 RPM below setting in bin file. Engine off, plug in IAC, clear codes. Should end up 20 to 40 IAC counts CL idle.

My way, or I should say another way I found that works is while warmed up CL idle and looking at Scan Tool/TunerPro and IAC is low or high, so if low/no counts close throttle blades, if high, open throttle blades. 1/4 turn, turn key off 10 seconds, this clears the power off which is usually 5 seconds and resets TPS to 0 %, start engine and rev till closed loop, let idle and check IAC. Rinse Repeat. I can do other things while doing this, usually have my next few steps/checks already planned, don't get to close to me while working on one, I may change dierection and knock you down! :laugh:

[duecepipes22]

Haha I'll remember to stay out of your way if you are adjusting your idle!

Glad I asked about the methodology of getting that adjusted. I got mine adjusted so I have about 20 iac counts. I had to readjust my TPS because it didn't reset itself. I was also able to order my burn2 today so I'll finally be able to figure out what my bin looks like.

In that data log I posted on here, why is it that there are only values in one of the MAP columns? Is something not right with my data logging that it didn't fill in all the boxes? Also can you look at your spark advance to see what the timing is ACTUALLY doing or can you just look at the bin and see what its SUPPOSED to be doing?

[EagleMark]

TPS voltage will not reset. It is the TPS% that resets in the ECM to 0.

Well the reason the BLM history table was only doing one line was this ALDL data stream only has MAP voltage, the value for MAP kpa is a conversion from voltage and it was wrong. I fixed it.

But the BLM history tables in HD or LD do not match the fuel VE table so they need to be redone. Wish I had time but not going to happen till fall! Here's a write up I did on how to make them and you can readjust to match the VE table.
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?444-Making-History-Tables-in-TunerPro

There is also no spark advance in the ALDL data stream so best way to see where you are in bin is to use data tracing, I set up the spark table, take a look here on how to use it and make it work for other items.
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?356-Enable-data-Tracing-in-TunerPro-How-To

I just looked at a $4F bin file Main Fuel VE table and it is by far the worst thing I have ever seen in my life!!! Click on graph to see? The GM engineer who built the fueling for this should be hunted down and shot! Main Spark is also a disaster... I know what we have today is better then what they had then, but this is ridiculas! Rocky Mountains are a flat plain compared to these...

Maybe while I'm in the hospital with no internet for three weeks I will do a write up on how to build a smooth spark and fuel table to start with...

[duecepipes22]

Hospital for 3 weeks? I hope everything is OK!? Thanks for fixing the file!

Well hopefully the guy that burned my chip worked out my fuel table but in all reality, who knows what he did. Hopefully my burn2 will be here in a couple of days so I can have a look and upload it on here, of course you will probably be stuck in the hospital when I get it so I will try to patiently wait!

With my lack of knowledge, I'm not sure what you mean by "the BLM history tables in HD or LD do not match the fuel VE table so they need to be redone" but I'm always up for learning so I'll look into it.

I hope everything goes well in the hospital and thank you so much for all your help!

[EagleMark]

Lots of guys to help while I'm sidetracked. Read the history table thread I made and it'll get you into what is possible with TunerPro. Basics are done! Just that MAP and RPM do not match VE table, once you read and look you'll see what I mean.

[duecepipes22]

I got my Burn 2 in the mail today. I hooked up my chip and tried loading my bin with flash & burn and then opening it with tunerpro but when I open it with TP it doesn't show that there is anything on the chip. All my numbers are 0. Do I need to change my chip and buffer addressing? Right now my chip is 000000 to 00FFFF and the buffering is 000000 to 000000.

[RobertISaar]

trying to read a 2732? or something else?

[duecepipes22]

No, I was reading the right one... I checked it several times to try to avoid looking like an idiot. I might have it working though. I loaded a different bin on flash and burn for my truck and burned it to my spare chip and some different address numbers came up. I then used those address numbers to read my chip and I was able to get my bin off it. I'm a little confused though because there is a blue light on the Burn 2 that turns on sometimes and doesn't other times. I've had it stay on even when I took the chip out and another time it never turned on whether the chip was in or not. Do you know when it should be on?

[RobertISaar]

IIRC, the light will flash 3 times, then a slight pause, then flash 3 times again, when the chip is in correctly.

or at least that's the way it works for the 29F040.

[duecepipes22]

Interesting... I'll have to play with it a little more. Do you know why I wouldn't have VE tables in TPRT? I have a main fuel table and thats it. Mark had told me to make a BLM history table to match my fuel VE table but I don't think I have one.

[RobertISaar]

main fuel = main VE. same thing, different term.

[duecepipes22]

So much for avoiding looking like an idiot.... So is that the only fuel table I have to work with then? I uploaded a $42 mask and it has 3 different fuel tables. Is that because people have gone into more depth with that mask because its more common? Thanks for the help BTW!

[RobertISaar]

depends. certain masks have different setups. some have idle + main, some have idle + main + adder, some even go alpha-n for idle. personally, for nAst1 i setup a set of 3 tables, 20-100kPa in 5 kPa increments, 400-2000 in 100RPM increments, 2000-8400 in 200 RPM increments. no differentiation between "idle" and "main" other than the reflection of the MAP sensor and RPM moving around. totally overkill, but it's an idea of how wildly different you can find things.

[duecepipes22]

Yikes... I'll stick to the basics for now. After a long wait, here is my .bin Its the "custom tune" I paid big money for a while back but it looks a lot like some of the other bins I found on here.

[duecepipes22]

Do you know how to delete the EGR from the tune? I have a $4F mask as the title says and I read to just set the parameters so that it doesn't kick in, but it looks on my bin like there is more to it than that. After a second attempt to seal up my EGR gasket leak and failing, I decided to put a block off plate on it and delete it from the tune.

[EagleMark]

That bin you posted has an exact Main VE table as a stock bin, so not sure what you paid big bucks for?

If your seeing all 0 in Main VE something is way wrong, there was a bad $4F XDF floating around awhile ago so check to see you have the one in the $4F info thread I am using and it is working fine.

$4F has one Main Fuel VE table. $42 has a VE1 and VE2 adder, the reason there is three in the XDF is one is corrected to hack, one is what everyone has been using for years, look at the Read Me for details. Hack was reversed MAP RPM when originally done but still works correctly when tuning luckily! So theres 2 VE1, one correct, one reversed, if you make a change in one it is changed in other. No biggy...

To disable EGR in $4F look for "EGR - Enable Temp" in scalers and raise temp to max and it should never come on. I usually look for other EGR tables for fuel or spark corrections when EGR is enabled and zero them as fail safe.

I've never used a burn 2 but like all chip burners once you get offsets set correctly for bin size to chip it'll work fine till you use a different size bin or chip.

[duecepipes22]

I wasn't expecting to hear from you yet! Everything going ok?

I guess I'm not too surprised that its the same, I'm starting to think that the guy just bumped the timing a little and called it good. I compared my fuel table with a stock one on Tunerpro and it looks like there are 5 cells that are different, but thats it.

I've got the burner figured out now, got my EGR deleted and I bumped my idle up a little... its still rough. I'm having new bushings put in my throttle body on Tuesday so hopefully after that I'll have it running right so that with your help (hopefully) I'll be able to get my fuel table figured out?

[EagleMark]

All is better then well thank you!

I just compared VE to first bin I had in $4F and it was identical.

There are some tricks for better idle, but normally not needed on a stock motor without mechanical issues, needed for cams and such but we can learn!

What is your IAC count at idle? What is your TPS voltage at idle. When I say idle I mean fully warmed up and driven. When ever we talk about data it is always warmed up and driven, this is a major flaw many people make when tuning. Everything is an adjustment from here. I have found totally warmed up is not enough, driving 1 mile puts it in the zone! OK maybe 1/2 mile or at least a blast around the block on warm day. I beleive this is do to wet intake and warming up...

[duecepipes22]

So does that mean that my VE table is crap for a motor that has been bored, different cam, headers, very free flowing exhaust, all the TB mods... basically everything has been changed except intake and heads? In other words, I got taken?

So do you think I need to accommodate for having a cam, even if its pretty mild? My IAC count is between 20 and 30, TPS voltage is .57 (I elongated the wholes to make it adjustable) In my bin, it says "IAC-%TPS for Closed Throttle: 1.20%" should I change that to 0% since I have it adjusted to that? I always make sure its warmed up and locked into closed loop before checking anything or data logging.

I dropped off my throttle body and a carb shop today to have new bushings put in and his response was "yeah, that thing is pretty bad" so I'm hoping my idle problems were stemming from a vacuum leak through the bushings.

[RobertISaar]

yeah, with all those mods, the VE table should require some siginificant changes....

[duecepipes22]

yeah, with all those mods, the VE table should require some siginificant changes....

OUCH, I was taken! Looks like I paid almost $400 for a chip adapter, EEPROM and a little timing advance!

[EagleMark]

So does that mean that my VE table is crap for a motor that has been bored, different cam, headers, very free flowing exhaust, all the TB mods... basically everything has been changed except intake and heads? In other words, I got taken?

So do you think I need to accommodate for having a cam, even if its pretty mild? My IAC count is between 20 and 30, TPS voltage is .57 (I elongated the wholes to make it adjustable) In my bin, it says "IAC-%TPS for Closed Throttle: 1.20%" should I change that to 0% since I have it adjusted to that? I always make sure its warmed up and locked into closed loop before checking anything or data logging.

I dropped off my throttle body and a carb shop today to have new bushings put in and his response was "yeah, that thing is pretty bad" so I'm hoping my idle problems were stemming from a vacuum leak through the bushings.With 20 to 30 counts there is not a significant vacuum leak. 0 would be significant.

TPS% is just a calculation in the data of this bin, not actual so don't worry about 1.2%, that is about correct for .57 volts


yeah, with all those mods, the VE table should require some siginificant changes....Yup...


OUCH, I was taken! Looks like I paid almost $400 for a chip adapter, EEPROM and a little timing advance! Ouch!

[duecepipes22]

Could my erratic idle be an ignition problem then? My distributor, ignition module and coil all have 263,000 miles on them. It seems to run fine past idle and it idles smooth in closed loop and when the wire from the ecm to the distributor is unplugged. I'm crossing my fingers that there is a vacuum leak but I think I need to prepared in case the TB isn't the solution.

[EagleMark]

Very well could be? I'll bet that pickup coil and connections are solid green goop, check shaft to see if loose.

[duecepipes22]

The terminal on the coil was green when I replaced the plug wires about 3 weeks ago... I'm going to check it out today and hopefully test it, I'll check the dizzy while I'm at it. I'm supposed to get my TB back today so I want to do some data logging... I looked at my BLM history table and it looks like it matches up with my BIN. It has all the same numbers for my map and RPMs so it should work, right?

[EagleMark]

Yup, if the BLM table looks exactly like the VE fuel table it will be correct for adjusting each cell.

I just remembered there is another issue with old small cap distributors! Look directly down at reluctor and see if it is cracked, the black part which has the metal points coming off it. Also see if this is rusty and touching terminals.

[duecepipes22]

Thanks Mark, I'll check on those things on Monday, I'm heading out of town for the weekend.

I got my throttle body back today and sure enough, it didn't help... still have a rough idle, although I'm not so sure that my TB/spacer are sealing up good enough because if I shoot some carb cleaner at them, it still affects the idle a little.

Anyway, I did another data log tonight with the throttle body fixed to see if it changed anything. Is there any chance that since I'm running pig rich at idle, that could cause the idle to hunt around trying to correct itself?

[EagleMark]

Yeah, it'll wet everything and throw off the O2 as well, but unless your shooting carb cleaner near the IAC intake port of TBI you got a vacuum leak! What works better but is dangerous so be carful and do at own risk if you feel safe is starting fluid. Not near any sparks or altenater, short little bursts long arm away well make the motor rev, then you know for sure where the searching idle is. Or propane tourch, on high not lit of course... is safer. I've never been hurt with short bursts of starting fluid, but it finds leaks fast! No doubt when motor revs! Short burst, Vrrooom...

[EagleMark]

That is pegged rich a lot, so if you have a vacuum leak the O2 sensor reads all the air and adds fuel, double whammy is MAP see's low vacuum, higher MAP and thinks it's a load and adds fuel. Or fuel pressure is way to high? Is this a stock motor? Something is wrong...

[duecepipes22]

Starter fluid is actually what I originally used until I ran out... OOPS! Wasn't using short bursts! I'll get more and try that again. Could a very minor leak be causing this? My EGR leaked way worse than what I noticed this time and fixing that and the throttle body didn't help at all!

The motor isn't stock. Its got stock heads that were shaved just enough to true them up and intake manifold but then its got an open element filter, mild RV cam, the basic throttle body mods, long tube headers with true duals, H pipe, no cats and glass packs. My fuel pressure should only be at about 13 psi right now, I checked it no too long ago. I've got some ticking from the headers that I thought could be an exhaust leak, but people keep telling me that just how headers sound.

[EagleMark]

All those mods would not cause this and the cam is not big enough. Your MAP reading and idle are fluctuating from 35 to 45 but idle IIRC was only moving about 75 RPM, IAC was low at like 9 to 20 counts. BLM seem to rise as RPM and load increase to where they should be. All indacations of vacuum leak. Hard to do over the internet but looking into vacuum leak is something I would look into.

My headers never ticked? Does this tick happen on O2 sensor side?

I hate to say this but on a SBC you can have a vacuum leak under intake not detectable without a smoke machine. You could pull all plugs and look for one that is differant as well for an individual or pair of cylinders off. In a case like this I would start with four on O2 sensor side.

[duecepipes22]

Well I know for sure one of my TBI base gaskets is still leaking a little, on the O2 sensor side, either above or below the spacer but since I can't seal them up, I'm going to put a bead of silicone around the top and bottom of each gasket to help seal it up... that should take care of it!

Not sure which side the headers tick on, I can only hear it when I'm in the truck and its under a load. They are 14 gauge so I thought the ticking wouldn't happen... maybe it is a leak? I'll look into that a little more.

Boy I hope its not the intake manifold.. Can I check that with the starter fluid or do I have to smoke test it? I did notice a while back when I was checking spark plug gaps that cyliders 6 and 8 looked a little wet. I re gapped them and drove it a little and they looked fine when I checked them again. Not sure what to think about that but I also recently changed plug wires because they were getting bad and since plug wires 6 and 8 were wrapped together, they could have been messing with eachother.

[EagleMark]

Any of or all those things add up to a mechanical issue you can't tune out. Silicone around spacer is not going to do the trick there. You need some new gaskets, clean flat surfaces and O2 sensor safe sealer designed for fuel on both sides. Some fine grit sand paper on a really flat surface and polish all surfaces in circular motion will usually show you a defect that is causing the vacuum leak.

Bottom of intake is inside motor, can't test that with starter fluid... that would be last resort test but have to have a smoke machine to do it. If all machining was done properly it should not happen...

[duecepipes22]

I've tried 2 different sets of gaskets but they haven't sealed up. I'll take them off again and try polishing up the surfaces. So you don't think it would work to put a thin bead of gasket maker between the spacer and gasket and gasket and manifold? By 02 safe sealer do you mean a different sealant to put between there? $6 isn't bad to pay for gasket, but the cost is starting to build up after trying 2 pairs of them and the leak still isn't fixed! I'm just keeping my fingers crossed that its not the manifold leaking!

[EagleMark]

O2 sensor SAFE gasket sealer so the fumes do not ruin the O2 sensor, also has to be fuel contact type. Polish all surfaces on machined type flat surface, machine shops have flat tables, I have a piece of billet alluminum, machined and polished and checked on the flat table at machine shop and use it. Before that I had a 1/2 inch thick aluminum plate that was fine... Look for and keep polishing out inperfections. 5 circles and rotate part 90 degrees, five circles rinse and repeat till you did it 360 degrees, look for inperfections. Start with 300 emery cloth, if you find a big inperfection use 100, then when gone polish with 300. Then a layer of sealer on both sides of gasket. Tighten up and let dry overnight. I don't like doing it this way or all the work but once a gasket leaks once I do this and it never has failed... thank God I never had to take one off too...

[duecepipes22]

I think I got it all sealed up. I put new gaskets above and below the TB spacer and I can't find any spots with the lighter fluid that change the idle. The idle is 75% better now but the tach still has a little bounce to it. I was going to data log today but the computer battery was dead, but hopefully later in the week. I'm going to retorque my intake and header bolts tomorrow and and turn down my fuel pressure a bit to see if any of that helps at all.

[duecepipes22]

Well I tightened my header bolts today, attempted to tighten the intake bolts but realized it was more of a hassle than I realized so I'm putting that on hold, and I decreased my fuel pressure a little bit. I did a data log as you will see attached and I'm not sure if I've gained any progress or not. I was hoping you might be able to tell??? I was also looking at the flow sheet I got when I had my injectors flow matched and I didn't know if the numbers would help you determine why I'm running rich despite using a stock fuel table on a mildly upgraded motor.... injector 1 is 859 cc/min and inj 2 is 861 cc/min @ 20 psi, but I'm running them around 12 psi. I have no idea if that helps or not, but now you know.

[EagleMark]

Still a lot of 105 BLM which is MAX low!

But I just looked at your main fuel VE table and it is WRONG! Corrupt or just a big mistake... from earlier post TPS Tune Bin? Look at your main fuel table in graph mode...

[duecepipes22]

Isn't that the fuel table that you said was identical to the stock one? When you say wrong, are you referring to the fact that it dips way down in the middle?

[EagleMark]

I take that back.. all stock bins for 5.7L $4F Main VE table is WRONG! Corrupt or just a big mistake! How the hell would you tune that? I would have to build a new fuel table before I started with one of these. Here is another GM SCREW UP!!! What a joke...

[duecepipes22]

Uh oh... so now what do I do? If its actually that bad, would the truck even run? Other than the idle, the truck runs fine. In my mind, it lacks power, but it doesn't do anything that would seem problematic. I'll pull the chip again tomorrow and pull the bin off and upload it on here just to make sure something didn't get corrupted.

[EagleMark]

Well nothing there made sense? So I looked at the hack and the XDF is built wrong!

Your still way rich but until this XDF gets a rebuilt I wouldn't know how to take fuel out of VE...

[EagleMark]

I fixed the XDF and took some fuel out of the lower VE table for ya...

[duecepipes22]

I sent you a PM but I'll burn the chip tonight and give it a try! Thank you!

[duecepipes22]

You must have smoothened the curve out big time... that looks way better. Unfortunately I won't get a chance to try it out until tonight. My original tune had the idle set to 525 at running temps but one of the generic bins I found on here had it set for 700. Does 700 sound about right for a manual transmission and could the fact that it was idling so low have anything to do with it running so rich since it was all fuel and little air through the IAC?

[duecepipes22]

I got the chip burned and took it for a quick cruise, here is the log. It seemed to run a lot smoother but still a little jump where it goes from still slightly rich to perfect. It looks like it leaned out a little too much in a few spots, is that a cause for concern?

It idled pretty good before I actually drove it and at stop lights, but once I got back into the garage, it started "searching" again. Based on what you see in the log, is there anyway it could be an ignition problem or are you still leaning towards a vacuum leak?

[EagleMark]

If you have a manual you should always start with a manual bin and 700 seems correct, the lower Idle is for auto.

I'm not sure what's going on? You've got same cell change from 117 to next frame 140? Is running a lot better by logs though. There's not much advance in this chip at idle with spark bias, take a look at chip, I added another row for idle and adding some timing thoughout but also added some timing at idle, took away some fuel in those rich idle and decle areas. Look at it and give it a shot.

[duecepipes22]

Thats awesome, thanks again so much!

I gave it a try, here is the log. I think the extra timing woke it up a bit and the fact that its not bogging from running so rich, but it looks like its running pretty lean now from 1600-2400 rpm across the board and at 1200 in the higher kpa which makes me kinda nervous since its my daily driver. I also noticed that some cells have a range of over 30, could this be from a bad sensor or something or is that normal?

[EagleMark]

Before I do anymore are you comparing what I am doing? I don't want to make decisions for you I want to teach you and give some examples.

I'll look at the log but you do need to set your timing to 0 with timing wire disconnected! We can learn to get fuel dialed in, but I'm not sure at this point you have good fuel pressure all the time, maybe at idle. Have you changed the fuel filter lately? Hope there's not an issue with pump.

[duecepipes22]

Yeah I've been looking at everything you have done and trying to figure out how and why you do it. I'm not one to just sit back and watch, I'm here to learn.

My timing is at 0 with the wire disconnected. My fuel filter and fuel tank are about a year old, maybe 5000 miles on it so I wouldn't think it would be clogged already. The fuel pump is about 2 months old and its one of the vortec pumps (EP381) thats good up to 60 psi so I'm assuming its sufficient for 12 psi. I had checked the pressure about a month ago and it was rock solid but if you think it could be an issue, I'll pick up a pressure test kit from autos zone and check it tomorrow.

[EagleMark]

Well you seem to have the fuel and spark covered! I've not done a lot of work with this mask so I'm guessing the changes I'm seeing are Decel and DFCO parameters.

I would not be scared to drive it as is, BLM are not perfect but in ballpark. That little spark sure did take away some of that richness! Look at this bin and compare to your BLM history table after playing the log back. I added fuel to numbers above 128 and took away fuel from under 128, which was just idle. Then smoothed some.

Look at the main fuel table and your actually getting a torque hump already! This is good!

[duecepipes22]

I'm excited to give that a try tomorrow! I'll check on my fuel pressure too, just to be sure. I see what you mean about the torque hump... thats pretty cool and unlike ANYTHING I got from the other guys "tune". That doesn't actually show where the max torque is though, does it? Seems lower than I would have expected. Is that normal for timing advance to dry things up like that?

I'm looking at the compare bins and I see exactly why you are adding and subtracting fuel in each cell except in the 30 kpa, 800-1600 rpms, it was lean there, but you subtracted a little more fuel. Does that have to do with the deceleration enleanment? Also, are you using an equation to figure out how much fuel to add or subtract? I've seen different equations online but whatever you are using seems to be dialing it in very quickly.

Yeah, I've got the fuel pretty well covered, but the only things that have been changed on the spark end is plugs, wires, cap and rotor. The dizzy, coil and module are all original as far as I know, which means 263,000 miles of experience.

[EagleMark]

The tourque hump is lower then actual peak tourque but the start of it need for MORE FUEL, its nice to see when it starts to form when doing a tune, most guys just overlook the need and smooth it through and let ECM/PCM do all the work. If you get VE fuel and spark set right it just runs good all the time, even open loop.


I'm looking at the compare bins and I see exactly why you are adding and subtracting fuel in each cell except in the 30 kpa, 800-1600 rpms This is the area that has been doing weird stuff, changing BLM for rich to lean, it's below idle and only obtainable at deceleration. So I went by lower numbers. When your looking at your BLM history table there is a minimum and a maximum take a look at that feature. What I saw was rich during decel but when you accel it went lean, so I beleive it is rich, have to look more into Decel procedures and see if there are some tweaks there.


I've seen different equations online but whatever you are using seems to be dialing it in very quickly. I usually tune live and rough in a tune very quicky, it's taken years and 100s of tunes to get there. I just did yours the same way, knowing about what it needs here and taken away from there. I've forgotten formulas but we should go over it here somewhere. Once I rough it in I kill power to ECM/PCM so it looses learn, maybe need one more rough, kill power to loose learn again, then do a good datalog and use one of Dave W spreadsheets in excel or Open Office which does the calculations for you. I love Dave! But he hasn't done one for the $4F VE table yet and I have still not had time to learn speadsheets to do my own... don't even want to think about it till winter!!!!


Is that normal for timing advance to dry things up like that? Yes! I wish I knew the technical reason but only know it works during tuning. That's why guys go back and forth constantly. Once you know it's running safe I usually add some timing, not all, to get it over with and add fuel, but like I said I do it live. You've still got room for more spark but that is up to you, I don't like to help push limits of spark when I am not there!

I've even got my son trained to drive while I tune, we have our route, he takes directions well as what I want him to do with gas pedal. If there are no mechanical issues, which usually there is, I can do a cammed built motor including idle in under 3 hours. Ones that go on to dyno are usually within 10% fuel/spark on the safe side. But that's 35 years mechanics, 25 years EFI and conversions and full time tuning for last 5 years and lots of friends here! :thumbsup: Several are on speed dial and answer phone for me any time I call. :rockon:

And I'm still a novice... but I live and literally dream this stuff! Really, I wake up shocked sometimes "That won't work!" Or run out to my laptop and do some work... :laugh: I know I'm sick...

Just got 2 more books for fathers day from my kid written by Greg Banish, would love to attend his school or the EFI university next summer in Seattle for a week.

[duecepipes22]

Wow.... I knew I had a ton to learn, but now I realize I have even more than I realize!

That makes sense with the torque hump because thats where I already noticed it start to pull a little harder even before all this tuning.

Should I be resetting my ECM before putting each chip in? I haven't been doing that because I still don't understand what the ECM "learns" vs what it just listens to on the chip. Such as, if its running rich and it knows it, why doesn't it just cut back the fuel rather than needing to cutting it back in the chip.

I've been looking at the min/max values with each log but had no idea how to apply them to tuning. I've seen Dave's conversion chart and attempted to learn use it with my mask and quickly learned that it either doesn't work or I have no idea how to use it.

I'm going to burn the bin from last night and give it a try today! As always, thank you for taking the time to teach me this stuff, I can't thank you enough!

[RobertISaar]

the MPFI V6 masks from ~1989 and onwards use a mode 4 command to reset all of the BLM cells.... i'd be amazed if there wasn't something like it in this application.

[duecepipes22]

Does that mean that it automatically resets itself or that I need to manually do it?

[RobertISaar]

well, aren't i observant.... 4F = 160 baud = unidirectional.

so, no, there won't be a command for this to reset the cells. you'll have to pull a fuse or the connector for the ECM to reset the cells.

[duecepipes22]

I just gave the new tune a try... I had disconnected the battery to reset things, which is the first time I've done that so I hope it didn't cause any logging problems. The numbers were looking great until I jumped on the interstate and cruised at about 2000 RPMs, then the BLMs went right back up to the 140s. I'm going to check my fuel pressure right now because I would have thought that with the fuel you added last time, I would have brought those numbers down. Here is the log...

[duecepipes22]

I also just confirmed that my fuel pressure is 13-13.5 (its a 100 psi gauge). It does have a very slight dip when I hit the gas, maybe 1 psi, otherwise its steady.

[duecepipes22]

I did a little fuel adding of my own since that last log and relogged, things looked better but could still use work. I'll do a little more work on the fuel and then data log and upload the bin and log to see if I'm doing anything right. Also, today while I was driving on the freeway (I wasn't data logging at the time) but my CEL came on, EGR fail. I turned my EGR enable temp all the way up in the bin but apparently it still tried to enable it. Any thoughts on that one?

[EagleMark]

That was probably the EGR test, it failed, turning off EGR won't help, have to look in bitmaskes and see if the bit to turn off the test is in the XDF. Or could fix EGR, it's not really a bad thing...

EDIT: It is in there "Option Word 1 - Bit 7 - EGR" uncheck that for now.

[duecepipes22]

Thanks! I got the EGR test taken care of. The only reason why I pulled it off was because I couldn't get the gasket on it to seal because of what looks like rust pitting, so I had a constant vacuum leak there. Its not necessarily that I don't want it, but my dad has a CNC so it didn't take much to make a block off plate and call it good.

I made some of my own adjustments to your last tune and did a data log. Here is the bin and log, mind taking a look? It seemed to run lean at first but by the end of the run, the numbers looked pretty good. Is that the computer making some adjustments of its own since I reset the computer before plugging in the chip?

You said I had room for more timing advance, how much more do you think I can add? My goal is to not make myself a 355ci gernade!

Sorry, I just realized I never included the files! I also just read about avoiding PE or disabling it, which I never made an effort to do, is that going to screw up my data pretty bad?

[duecepipes22]

Today I did a new data log with that same bin but I tried to stay really light on the throttle (but still hit the higher RPMs) keeping the TPS% down and I noticed with my log that my 2000 RPM BLM's across the board were all lower. (about 120) whereas in the last log when I was getting on it more, they were around 130. Does this have to do with The AE/PE settings and the added timing leaning out my BLM's? And when adjusting my fuel table, should I used the numbers from today that say that I'm running rich? I'll post today's log in case you want to see what I'm talking about. My log from the other day is above. Thanks!

Nevermind the sudden richness of that area, I just noticed while watching the log that the BLMs started to drop as soon as it threw an EGR code.

[EagleMark]

Sorry I missed your last post.

Couple things happening I see, some may be explanable? There's no ALDL data to tell when your in PE in this mask and all paremeters I see in bin file say it's still on, so got to turn off PE to get good BLM data. Second I think this is an Auto bin and from looking at your log I'm guessing you've got a manual trans? If so start with another manual bin and compare/copy over your fuel and spark and whatever. There's just way to many differences between auto and manual bin to even start and try, mostly IAC logic but also decel or DFCO etc... again throwing BLM data off.

Reason I say throwing BLM data off is your log started warmed up which is good, but BLM at idle were 136/lean, then later they were 106/rich? You may have some drippy injectors? Somethings wrong to get that big a change in warmed up data?

You went way rich before the EGR error code, and at that speed it looks like the bit 7 EGR test, but your last bin I saw it was turned off, so..... went looking at ALDL file and no bit to tell if EGR came on either? Got to disable the EGR, or more to get good BLM data.

[duecepipes22]

I'll get started with a manual bin right away.

I've had the EGR shut off on all of the bins, including the "Option Word 1 - Bit 7 - EGR" in the last couple so I don't know why it continues to cause problems.

I think something else is wrong because I made a few adjustments to my upper RPM range after doing that last log and I just logged again and everything was rich again! When I started the log it looked good but rapidly turned rich. Like you had mentioned, I'll check my injectors, but it seemed to be running fine so I don't know what to think! I also had some knock in the last log that I posted, which I hadn't been having. I'm starting to see some of the frustrations that accompany this!

[duecepipes22]

I think my problem may be that a sprung another vacuum leak! I just retorqued my throttle body and EGR block off bolts and they both seemed to be pretty loose. Unfortunately I think the idle was still changing with the lighter fluid spray... here we go again, but I'm assuming I found out why my BLMs were off again. Would that make sense?

[EagleMark]

Yup! I knew something was wrong...

I thought I was daring with short bursts of starting fluid? Your actually useing liquid? I dono bout that... be safe please! Really the safest way I know is a propane tourch, sometimes it needs to be on high and close up with wind from fans. Safety glasses, gloves and long arm, really reach in to it and keep your face away!!! Please be safe...

[duecepipes22]

I've been using spray can starter fluid. I figured, besides blowing up my face, truck, garage and half the neighborhood, whats the worst that could happen?.... I'll reconsider doing it that way. I'm thinking about just calling around to see if any local shops do smoke testing and what they charge for it.

I grabbed the "AWSY 92 C-K-P Truck 5.7TBI 5 speed" bin you have on the $4f thread and inserted my fuel and spark tables as well as what I have been doing to delete my EGR. Would there be anything else to change or do you think it looks good? I couldn't see any other differences, but then again, I wouldn't know what to look for.

[EagleMark]

Very short little bursts of starter fluid with your hand fully extended, that way if it finds ignition it's a very short little explosion!

It's still doing the same thing? Warmed up, start log, little lean 134ish, then get's almost perfect then ends up pig rich? I've never seen that before? Maybe spark going away?

[duecepipes22]

I haven't relogged with this bin since fixing the vacuum leak (if it is fixed, fingers crossed). I feel pretty confident that it will be better once its fixed, but then again, I'm just a newbie. Like I've said, I wouldn't be surprised if the spark was failing considering all the miles, but I would think that it would run a little rough if that was the case. It still accelerates/drives perfectly smooth.

[duecepipes22]

I just got done doing a data log after attempting to fix the vacuum leak. It seems to be doing better and according to the BLMs it looks like its running less rich again. However, while I was cruising at about 2000 RPMs my EGR tried to kick on again and instantly the BLMs went from 128 to 109. I cant figure out how to get that thing to stay off!! I've got the EGR enable temp all the way up, the EGR on and off TPS% are both at 0 and the Option Word Bit 7 is off.

I guess at this point I'm also confused as to why my BLMs were back to perfect at 2000 RPM and above (prior to EGR trying to kick in) yet below 2000 it didn't lean out as much after fixing the vacuum leak.

[EagleMark]

Yeah that was doing way better! Why does the EGR keep coming on? Post up your bin and we can take a look, for some reason it is not disabled, we may have to 0 out tables or?

Below 2000 RPM is much higher vacuum, so you had a much higher vacuum leak. At least they are consistent now and tunable.

[duecepipes22]

I haven't 0 out tables yet because I didn't want to make something go really bad if it tried to kick on and I obviously don't know what I'm doing.

As far as vacuum leaks go, I obviously made it better, but the numbers didn't come back to near perfect like they were so I think I still have one. Unless there was a little leak when we started with the tuning and now that its fixed, the numbers are off? I hate to say it, but I already noticed some wiggle in the throttle shaft and I just had new bushings put in about 2 weeks ago!!! Luckily the guy said he would try putting some harder bushings in for free. Obviously that could be another source of leak.

I noticed a couple of other things today while messing around with it that I'm not so sure about. My volt meter twitches as the same rate as my turn signal whenever I turn the signal on, maybe its always done it, but I just noticed it now. The other thing is that I pulled the PCV valve and breather to try to feel for vacuum (I know I don't want to have that) but what I noticed was that if left my hands over the holes for a few seconds, when I pulled my hands off, there was a quick little rush of air. It did this right after starting it for the first time today but I'm not sure if its just doing that because the PCV valve wasn't on there to pull the air out of one side?

[gregs78cam]

Not that I think it will fix the EGR issue but raise the EGR on TPS to 100% or what ever the max is on the scale.

[EagleMark]

I've had the EGR shut off on all of the bins, including the "Option Word 1 - Bit 7 - EGR" in the last couple so I don't know why it continues to cause problems.
Wasn't turned off at all in the last bin I looked at?

[duecepipes22]

I just took it out for a run with the EGR on TPS% at 100% and the EGR never tried turning on so thanks!

Mark, which bin did you look at? All of my most recent bins I've had the EGR on temp maxed out. Are you referring to the Bit 5 code 32 flag? I've left that on so I know if its still trying to turn the EGR on, should I have that off too?

One other thing, I regapped my plugs today (most of them were close to .050 and I should be at .035) back to .035 and did a data log (I lost all my data because my computer died at the end of the run) and it seemed to idle a little better but my numbers were even more rich. Does that mean that now I'm not burning all the fuel that we just started adding to it because of the smaller gap? With my old stock ignition, I know I don't want to be running that wide of a gap but it seems like the BLMs preferred the wider gap.

[EagleMark]

I've got TPS Tune4.bin in my TunerPro history so I think that was last I looked at. Glad the EGR issue went away.

IIRC bigger then .035 spark plug gaps was a phase manufactures went through? Not really sure if newer cars still do this, I know it went up then back on vehicles I had and work with. I can't remember last time I gapped more then .035, less with boost.

Also everyone here knows my word is not an end all, I can be proven wrong and welcome the opportunity to more knowledge...

[RobertISaar]

i run .060 with 9.6:1 static compression.... the GM DIS can make some serious voltage, so it can run those gaps easily.

[EagleMark]

Back in 1995 is when I remember this phase, then gaps went back? Don't know the whys?

DIS is good stuff but lots of ignitions can jump half inch, does it really help ignite a highely flammable mixture under pressure?

[duecepipes22]

Good points... I know mine is supposed to be at .035 but a couple months ago I decided to open it up to .045 and see what happened. I wasn't sure if I was a victim of the placebo effect, but I actually thought it ran worse so I reduced it to .040. Now either the cheapo autozone tool was way off or they actually had opened up to .050. I trust that its strong enough to arc that gap, but with 262,000 miles on all my ignition stuff, I don't want to push it.

Does that make any sense though that it would suddenly run more rich now after decreasing the gaps? I'm finally going to grab an ohm/voltage meter today and start testing my ignition stuff.

[duecepipes22]

i run .060 with 9.6:1 static compression.... the GM DIS can make some serious voltage, so it can run those gaps easily.

Do you run that with the completely stock ignition? How many miles are on it? I would like to keep them a little wider, but I don't trust my stuff right now because of the weird logs I'm getting.

[EagleMark]

Your biggest issue with that many miles on a Small Cap distributor is the reluctor is probably cracked. If you take off the cap and rotor and the reluctor is clean look at it for cracks on black part between metal posts. There is also an issue of distributor gear wear, shaft wear, green corrosion on pickup coil and wires.

The best thing you could do for all the work you have into that motor is a new GM distributor.

Take off the coil wire on coil and see if it is also corroded.

Your way beyond service life of those parts...

[RobertISaar]

Back in 1995 is when I remember this phase, then gaps went back? Don't know the whys?

DIS is good stuff but lots of ignitions can jump half inch, does it really help ignite a highely flammable mixture under pressure?

pressure = resistance. the more pressure you have in the cylinder(from both static and dynamic compression), the more voltage you need to reliably jump the gap. most noticable at peak torque RPM, if it's not making the jump. the 3100 and 3400s ran .060 from their beginning to end, 1993 to ~2005.


Do you run that with the completely stock ignition? How many miles are on it? I would like to keep them a little wider, but I don't trust my stuff right now because of the weird logs I'm getting.

yes, completely stock. just about to roll over 201,000. 2 of 3 coilpacks are originals, 1 was replaced in ~2002 or so.

[gregs78cam]

I just took it out for a run with the EGR on TPS% at 100% and the EGR never tried turning on so thanks!


YW. Every now and then I do get one right, even if it is by accident.

[duecepipes22]

Thanks everyone for your continued help!

I finally pulled my dizzy out to inspect things and sure enough, I have a crack in the magnet between the center of the reluctor and the star looking piece (not sure what its actually called) I've been searching all day to find a delco or delphi dizzy but I have found nothing! I will try the dealerships tomorrow, but is it possible to just replace the reluctor? There seems to be no wobble in the shaft, surprisingly. I'll probably do the coil and module while I'm at it too.

[EagleMark]

Last I looked for reluctor on shaft cost was same as complete distributor. Beware of cheap knock offs, this is an important part and really not that expensive to get correct piece.

[duecepipes22]

Apparently this is easier said than done because all the dealerships in my area said GM discontinued them and they couldn't even find anyone in the area that might have one lying around! Any other brands that you trust?

I actually just found a Delco one at Factory Motor parts... they want $393.89 for it!

[historystamp]

I use http://www.rockauto.com for my '93 Corsica.

Robert

[EagleMark]

RockAuto has reman Delco for $128. New Delphi for $175 and I have used the UNITED IGNITION WIRE for $102. but never checked EST module for timing... there's also MSD for about $175. I don't like A1 Cardone parts even though made in USA they only try to compete with China standards.

I also asked pmkls1 in another thread as he is a GM tech and seems to know how to get the GM replacement.

[EagleMark]

pmkls1 answered and gave the part number for GM Performance part, real deal no crap. Since I'm looking for one I searched around and best price I found was
http://sdparts.com/details/gm-performance-parts/1103952

[duecepipes22]

Thats awesome, its even cheaper than on Summit! Will that fit my '91 though? For some reason the delco on summit only fits '92 and newer and the ones on rock auto that you found didn't show up when I searched my '91. Thats an awesome deal though compared to what I was looking at! I just hope it fits mine.

[duecepipes22]

I use http://www.rockauto.com for my '93 Corsica.

Robert

Thanks! I think I found one of my new favorite websites!

[EagleMark]

Thats awesome, its even cheaper than on Summit! Will that fit my '91 though? For some reason the delco on summit only fits '92 and newer and the ones on rock auto that you found didn't show up when I searched my '91. Thats an awesome deal though compared to what I was looking at! I just hope it fits mine.Yes! I think the reason 1992 had a differant part number then earlier was the EST number was differant, but actually it was used as a replacement for earlier ones, it's a better timing EST. Distributor otherwise is identical.

The EST is the biggest factor of new copies of distributor, they are actually simple to build/copy, but some aftermarket EST are off by many degrees timing and not reliable! Some cheap eBay distributors have bent shafts and no bushings!!! :yikes:

Look how long yours lasted? Want another like that or one that may leave you stranded any minute?

[duecepipes22]

I have no doubt that I would rather go with a good one. I refuse to even buy one from napa, autozone or oreillys. So if I understand what you are saying, the '92 and newer ones will still work perfect for mine?

The delphi one on summit goes for $194. Does pmkls1 think the GM performance part one would be better than a delphi?

By the way, you guys on here rock and have helped me out way more than I could have imagined!

I also just noticed that the GMPP distributor says it has a steel gear for roller lifter cams. I don't have roller cam, will that still work?

[EagleMark]

Pretty much all yes! The only difference is the EST, which looks identical, but old one pulled three degrees timing after 3000 RPM, GM used the new one when ever needed and never looked back. IIRC number on new one is 048 and old one 069, if you didn't know you'd never notice, by this point in time it may even have a new number. Don't worry about it.

The cam gear for roller cam is melonized and excellent replacement for flat lifter cam, this was just discussed in another thead. Better choice. for all.

I wonder if the Delphi and GM performance are the same thing? Same part number?

[duecepipes22]

Great to hear all that! Sorry you had to pretty much retype the same stuff for me to understand. Summit has both the delphi and the GMPP, listed as separate parts. The delphi is part number cz20001 and the GMPP is 110-3952. Summit has the delphi for $184 and the GMPP for $283, so the sdparts.com GMPP is a great deal! I wonder if the GMPP is really that much better.

On a side note, I asked a jack wagon at summit yesterday about the delphi distributor and he said "nope" no way it will work, but he said the GMPP will work. Shows how great of help they are!

[duecepipes22]

Well I ordered the GMPP distributor and got it installed... truck won't run! It started at first but chugged a lot so I tried rotating the distributor and now it won't run at all and twice I had a flame shoot out of my throttle body! I think its safe to assume that my timing is way off, but is it safe to unplug my timing wire right now to try to get the timing back down to 0 or could it be so far off that I could blow the thing if the timing is too far advanced?

I don't know if I managed to put the distributor in one tooth off or what???

[duecepipes22]

Nevermind that! I got it running. I think the problem was that it was so flooded from the timing being off. I unplugged the injectors, turned it over for a bit, plugged them in, adjusted the timing a bit and it fired up!

Something I noticed though was that while I had it running with the timing wire unplugged and timing at 0* there would be an occasional flicker in the timing and a quick sputter of the engine... its a brand new dizzy, could it be the coil cutting out? Also, is about 22* at idle about normal?

[EagleMark]

22 is OK at idle, something else id wrong if you see a flicker in timing light and stitter of engine?

[duecepipes22]

Do you think it would be the coil? Theres nothing else along the way with the ignition and it does it with the wire unplugged so its not like it can be anything with the computer or sensors, right?

It sits perfectly still at 0* and every 5-10 seconds it will flicker about 10 degrees.

[EagleMark]

That's really hard to answer virtually... But from what your saying I'd be looking at ignition still. Stuff like that is hard to do in person even with an osilscope...

[duecepipes22]

I kinda figured that would be the case but it was worth a shot.
I had a different suspicion that maybe my coil or another wire was occasionally arching with plug wire 1, causing the timing to jump momentarily on that cylinder causing a misfire/sputter? They are new wires but the guy at Oreilly talked me into buying the BWD when I wanted the delcos.

[duecepipes22]

I just got done doing a data log again and the truck idled the smoothest its idled in a long time! I had no idle change when spraying for vacuum leaks either! What still confuses me is that the BLMs started out pretty good and then went rich again. My question is, how good is the computer at actually adjusting the fuel? My BLMs are low so obviously its reading rich and trying to lean it out and I pulled all my plugs today and some looked maybe a little too white and some looked perfect. Is that still a sign of a vacuum leak or is the computer actually able to adjust fuel that much to get it to run right? Heres the log if you are interested in having a look.

[duecepipes22]

Sorry guys for the slow update, I've been pulling my hair out with problems with the truck but after 3 weeks of problems, I think I got things sorted out and wanted to give you all an update. Truck is running great with the new GMPP distributor. My "flicker" in the timing was due to plug wires arcing. I've been through 2 sets of borg warner selects and a set of delco plug wires and I'm still getting a little arcing but I've done everything I can to keep the wires apart and it seems to be better. Putting a new set of plugs in helped the arcing too but hasn't completely solved the arcing from the boots to the block and coil to intake. Anyway, the dizzy works great and would thus far recommend it to anyone looking for a new one. I got my from scoggin dickey but they just increased the price about $40 from when I bought it a month ago.

On a different note, I just discovered turning off the PE delay in my bin and for the first time actually felt what PE feels like! Not sure what to put the other settings at but so far I like it!

I also have a question... I just enabled data tracing for spark advance and VE table and its working fine for the spark advance but for the VE table the black "marker" thing that shows where you are running only goes up and down in the 20 kpa column, it won't go over to the other map columns. I did everything the exact same as the spark advance but I can't get the VE to work properly. Any suggestions?

[EagleMark]

Look at the X axis and Y axis, it sounds like Map and RPM are swapped for data tracing.

Wonder if your coil is shot? Is that where arcing is?

[duecepipes22]

You are too quick for me! I just figured it out and was going to delete the question.... I realized I had accidentally clicked "load" instead of "manifold air pressure" for the x axis data type. Its working great now!

Its arcing from the coil to the intake and then a few wires are arcing from the boot to the head. It almost looks like the porcelain on the plug is lighting up. Its not as bad as it was before putting the new plugs in it but for 2 days after I put the new plugs in, it ran perfect and now I'm starting to noticed a slight miss again at idle.

As I said before, I messed around with some of my PE tables and scalars but I don't know if I did something I shouldn't have. Would you mind having a look at it to make sure I maxed out its potential without blowing anything up? I put the AFR at 12.5 because from what I read, it was a safe ratio for not being too lean or rich but I still don't understand how that can affect anything without having a wide band.

[EagleMark]

You really have to get the spark/arc in order before you do much or it's all probably in vain...

[RobertISaar]

indeed, improper spark will cause lots of odd issues... really messes with O2 sensor readings when it gets to the point of incomplete combustion. and since fueling is almost always in closed loop for a street-driven car, that's a problem. spark, to some degree, is closed loop as well(knock sensor).

[duecepipes22]

Do you have any suggestions for what might be going on? I've checked grounds over and over again. New dizzy, wires and plugs. Any chance these wires got carbon tracked while I was still using the old plugs? (by old I mean 2 years and 11,000 miles) Only thing I haven't replaced is the coil but would that cause arcing at the boots as well? I looked at my coil and it isn't cracked or have any burn marks on it.