Which P4 PCM should I use

[CDeeZ]

Okay after scrounging the salvage yard for the past few days I've managed to come up with four separate P4 PCMs

I have TWO 16197427 PCMs
ONE 16196395 PCM
ONE 16168625 PCM

Which one should I use? I'm getting really close to converting my 747 setup and I would like to know which PCM would be the best shot? I know these PCMs are all in the same family of P4's (at least I think), but is there one that I should use over the others???

[Six_Shooter]

Those are actually P66 PCMs (Some may call them "P6").

You won't see a functionality difference between them, that I have been able to find.

That being said, I would likely use the '7427, just because it's more common.

[dave w]

Either one will work. I think having an original V8 Memcal would be a good idea. I have a 93 K1500 I use to test PCM's with. I swap the Memcal with the correct tune for my K1500 and have tested 16196395, 16168625, 16197427, 16156390, and 16196396 PCM's without any issues.

dave w

[RobertISaar]

........................ hairsplitting mode engaged .........................

those are all P6. P66 = dual P6 processors. AFAIK, only the 94-95 LT1/L99, 93-95 3100/3.4RWD and 93-95 Northstar earn that title.

[EagleMark]

Has no one ever got a LT1 PCM to run a small cap EFI distributor or DIS yet? Maybe it's time for a HyBrid OptiSpark distributor on a SBC? :jfj:

I must be bored to think up an idea like that again... :rolleye: sure would run good though!

[RobertISaar]

if you removed the dependancy of the 180X signal and the cam signal(assuming you don't want to simulate/integrate it) from the LT1 PCM, then i don't see why it couldn't be done with either the dizzy or the northstar DIS.

[jameslleary]

http://i144.photobucket.com/albums/r183/jameslleary/80cc18ee.jpg

[EagleMark]

My bench... :laugh:

http://www.gearhead-efi.com/Fuel-Injection/attachment.php?attachmentid=2687&stc=1&d=1341297258

[JeepsAndGuns]

I think this has come up before in other threads (using a LT1 ecm)
Is it like a super nice or extra good ecm or something? Why such a big desire to put it on a diffrent engine if its made for a specific ignition system thats not swap friendly?

[EagleMark]

It's an excellent PCM, underhood waterproof, flash through ALDL, Sequential. Drawbacks for using it on other then LT1 engines is cam sensor and the OptiSpark distributor which is mounted to camshaft behind waterpump. Other then that it looks like a TPI engine with a way better TPI.

[CDeeZ]

Those are actually P66 PCMs (Some may call them "P6").

You won't see a functionality difference between them, that I have been able to find.

That being said, I would likely use the '7427, just because it's more common.

7427 it is then!


Either one will work. I think having an original V8 Memcal would be a good idea. I have a 93 K1500 I use to test PCM's with. I swap the Memcal with the correct tune for my K1500 and have tested 16196395, 16168625, 16197427, 16156390, and 16196396 PCM's without any issues.

dave w

So you can swap memcals between V8s with similar equipment, but different PCMs, is that right?


........................ hairsplitting mode engaged .........................

those are all P6. P66 = dual P6 processors. AFAIK, only the 94-95 LT1/L99, 93-95 3100/3.4RWD and 93-95 Northstar earn that title.

LOL


Has no one ever got a LT1 PCM to run a small cap EFI distributor or DIS yet? Maybe it's time for a HyBrid OptiSpark distributor on a SBC? :jfj:

I must be bored to think up an idea like that again... :rolleye: sure would run good though!

I'm not a fan of that optispark dizzy on the LT1 b/c it's expensive and if your water pimp goes south it usually takes the dizzy with it, but put that dizzy out of harms way, where a conventional dizzy goes and that would be cool.. Of course My ultimate plan someday is to go DIS.


http://i144.photobucket.com/albums/r183/jameslleary/80cc18ee.jpg


My bench... :laugh:

http://www.gearhead-efi.com/Fuel-Injection/attachment.php?attachmentid=2687&stc=1&d=1341297258

James, Mark, forgive my ignorance, but WHAT ARE THOSE?


I think this has come up before in other threads (using a LT1 ecm)
Is it like a super nice or extra good ecm or something? Why such a big desire to put it on a diffrent engine if its made for a specific ignition system thats not swap friendly?


It's an excellent PCM, underhood waterproof, flash through ALDL, Sequential. Drawbacks for using it on other then LT1 engines is cam sensor and the OptiSpark distributor which is mounted to camshaft behind waterpump. Other then that it looks like a TPI engine with a way better TPI.

Yeah, the 411 is a good PCM. I think it's a pretty common PCM used by the LSx swap guys. I think I'll run a 411 or similar whenever I get around to my 6.0 swap some day :rockon:

[EagleMark]

Those are insides of OptiSpark distributors.

You and many people have fallen for internet rumors of them. They are by far the most excellent and advanced distributor ever made, there is nothing better until DIS or COP. Rumors rumors rumors.

Just because a couple people said there Opti was wasted when their waterpump leaked is BS. First the maintence on an OptiSpark distributor is to inspect distributor and replace cap and rotor at 100K. Try that with any other distributor? Mine had 125k on it and I ran the engine and ran a garden hose on it for 20 minutes without issue. If you have one that the Oring seal has gone bad, do maintenece, if your water pump leaks it's no harm to Opti unless Oring has failed, do maintenece!

[CDeeZ]

I hear what you're saying, with maintenance it shouldn't be an issue. I have no experience in LT1 stuff really, but I knew someone who had an LT1 Fbody and was pretty good about maintenance and upkeep of his car since he was a geahead, but somehow, he did end up losing an optispark b/c of a waterpump failure. But ah well

[dave w]

So you can swap memcals between V8s with similar equipment, but different PCMs, is that right?

What I've done is use the same V8 Memcal that was original to my 93 K1500 5.7 in the following PCM part #'s 16196395, 16168625, 16197427, 16156390, and 16196396 without any issues.


I've done several TBI PCM upgrades, any one of the following PCM's part numbers 16196395, 16168625, 16197427, 16156390, and 16196396 will work! I recommend purchasing a TBI PCM that has a V8 memcal if your conversion is for a V8.

dave w

[CDeeZ]

Ok I think I understand. All the PCMs I picked up were from V8 trucks, all 5.7Ls I believe, so I should have all V8 Memcals

Just fired my 427 for the first time, runs rough, going back outside with the laptop and an adx file to try to see whats up....

[CDeeZ]

From one of my other threads:

Well the conversion is done but the truck idles like crap. Haven't even tried to drive it since it idles so rough.

I CAN'T connect to the PCM with my laptop now that I've done the conversion... I tested with a 6395 PCM, and loaded the .xdf and .adx files from the 6395 thread onto my laptop but still got nothing when trying to scan....

What am I doing wrong here? Why can't I connect to the PCM to scan with my laptop????

Am I not doing something right on the scanning for error codes? Did I screw up some pins when swapping them?

I also posted in another thread about 3 remaining wires I had from the pinover... Crank signal, A/T high gear switch, and the knock sensor wire from B7 on the 747 ECM... I'm pretty sure I just leave the crank signal, and A/T high gear switch unplugged, but what do I do with the wire from the knock sensor???

My new knock sensor should be here late today or maybe tomorrow, so that part isn't done YET, but I can't see that not having a knock sensor hooked up would cause it to run this bad? The ESC is still connected. I know I need to bypass it, but is that my issue here? I know in the conversion thread it says "(3*)= B.) Wire like 1995 C10 Truck, Bypass ESC (Blue to Brown) and useLate TBI/TPI 305/350 Knock sensor" But what does this mean?? Do you simply hook the blue wire into the brown wire at the ESC (Bypassing it), and what about that knock sensor wire from B7????

And finally, can someone tell me what this means from the 747 to 427 thread:"I would also like to mention that the orange Serial Data wire needs to berelocated from the top row, Pin "E" to the lower row, Pin "M". You will alsoneed to scan the vehicle like a 1993-1995 G-Series Van, C-Series Truck,S-Series Blazer, etc with Auto transmission."

Why can't I connect to scan with my laptop!?!?!?!?

EDIT: well I think I figured out why I can't connect to scan... I need to move my serial data from pin E, to pin M on the ALDL port... Sorry for overthinking this one guys! But can anyone else help me with my other questions regarding the 3 wires? And about that ESC bypass..... Just blue to brown and late TBI knock sensor, I understand that, but what about the wire from B7?!?!?!

[EagleMark]

Crank wire is not needed on 97427 PCM.


And finally, can someone tell me what this means from the 747 to 427 thread:"I would also like to mention that the orange Serial Data wire needs to berelocated from the top row, Pin "E" to the lower row, Pin "M". You will alsoneed to scan the vehicle like a 1993-1995 G-Series Van, C-Series Truck,S-Series Blazer, etc with Auto transmission." That's why no data! I answered that in other thread.

[CDeeZ]

Well I moved the orange serial data wire to pin M. Still nothing when trying to scan............... Now what?

Help me out here guys please. This is my only means of transportation and I'm going to need it in the next couple of days, I'd like to at least get it where it runs decent on the 427 W/O being in limp mode or throwing tons of codes.....

And about the wire from knock sensor wire from B7.... does it remain unhooked from the PCM?????

[EagleMark]

Turn the key on without starting the engine and watch the check engine light. It should comeon, blink and stay on steady. If not there is an issue.

[JeepsAndGuns]

Yes, what is the check engine light doing? Is it blinking really fast? I know there has been a couple times and I goofed up and either didnt get a chip in place correctly, or forgot to put it in at all (lol) and it would start and run, but run like crap, check engine light blinked like crazy when I turned on the key, and stayed on when running. I also could not get aldl connection when it was running like that.

[Six_Shooter]

There's no such thing as a "good dizzy". :tounge:

[dave w]

Only three wires are needed to the ALDL connector on the '427 PCM conversion. Pins M, A, and B. Remove the others and make electrically safe by covering the exposed ends with heat shrink.:thumbsup:

Elimante the Knock Retard and ESC Error Code in the PROM Programming and don't worry about the knock sensor wiring for now.

I triple check the pin wiring to the new PCM, get just one pin wrong and that's no fun!

dave w

[EagleMark]

There's no such thing as a "good dizzy". :tounge: Ouch...

[CDeeZ]

Key on, engine off, CEL comes ON, goes OFF, and STAYS ON.


Three wires. Okay. Maybe that is why I couldn't scan with laptop?? I'm going out to eliminate other wires after I post here and grab some bins.


I have double checked the pin positions and they're good. I will do away with the ESC stuff at least until I can get this PCM to act right.


My G1 adapter from Moates came in the mail today so I can do some custom bins now for the 427
I'm going to just try a 5.7L A/T bin for now.

[CDeeZ]

Welp I removed all wires from ALDL port except M, A, and B. Still can't connect with laptop to scan... It's been a while since I set up my baud, com ports etc so I'm a lil rusty... Am I not able to connect b/c TPRT is still set up for the old 747 at 160 baud? How do you change that for the new 8192 baud of the new PCM, I forget.

Also, with the G1 adapter installed, I get no CEL whatsoever and the truck cranks and just dies. What is the issue now?

EDIT: I was installing the PROM backwards. Before anybody gives me grief about this, let me just say that the PROM goes in the OPPOSITE direction in the ZIF as compared to the 747, so easy mistake to make. The G1 seems to work, CEL goes on, off, stays on before cranking, doesn't come on while engine is running. It runs very rough still. I have BJLH.bin running it, with knock retard disabled and 43 ESC error disabled..

I'm going to check the pins a third time but I know they're right.

Still can't figure out why I can't scan it though?

[CDeeZ]

I've checked the pins at least three times, they are right.

Does anyone know why I can't connect to scan when I could with the 747?

[Six_Shooter]

There's nothing to change in TP RT to go from 160 baud to 8192 baud. Just load the correct ADX.

Have you tested for cable connectivity in Tuner Pro Preferences? You may just not have the proper com port selected.

[CDeeZ]

Thank you, I finally got the laptop to connect to the PCM, probably wrong ADX... I was able to connect with "A218 Trans1 $0D TP5 v250.adx"...

I'm seeing a bunch of error codes... All A/T related... The history tables, and Monitors features in TPRT are not working for some reason like I'm use to seeing them when logging with the 747 ECM... Is there a more complete/better ADX I should be using? The History table is actually totally blank. Weird.

[dave w]

I've checked the pins at least three times, they are right.

Does anyone know why I can't connect to scan when I could with the 747?

Is there a chance you can use a different vehicle to check the ALDL communication with? I'm lucky, I have a test bench to verify ALDL communications. Maybe you have a neighbor who has an OBDI vehicle you can check to see if your ALDL communication is set up correctly?

dave w

[dave w]

Thank you, I finally got the laptop to connect to the PCM, probably wrong ADX... I was able to connect with "A218 Trans1 $0D TP5 v250.adx"...

I'm seeing a bunch of error codes... All A/T related... The history tables, and Monitors features in TPRT are not working for some reason like I'm use to seeing them when logging with the 747 ECM... Is there a more complete/better ADX I should be using? The History table is actually totally blank. Weird.

Try this .adx

dave w

[CDeeZ]

Well I was finally able to connect "DA: Connected" in TPRT, but I couldn't really figure out why the history table was blank and monitor was nothing... I was definetly connected though, I could push gas pedal down and watch TPS change..

It starts and idles now, VERY VERY ROUGH, and smells EXTREMELY RICH....

I was hoping that a 5.7 bin for one of these newer PCMs would be good enough to at least drive the thing while I slowly ironed out the tune.

[CDeeZ]

Just saw your post after I posted, going outside to try that ADX right now. Thank you

[CDeeZ]

Tried that ADX and it has the history tables but still nothing for monitors?

I think I might be on the track to getting somewhere.... I captured a log, and my BLMs were off as I expected for a basically stock tune, but some were like 90!!! How can this be so far off when the bin I'm using is so close to my combination?!?! I noticed during my log that I got an EGR error code so I will now disable that as I have long since trashed the EGR vavle...

QUESTIONS:

1.) How do you guys know which definition to use when there are so many of them for any given ECM?


2.) I would think that this thing running so pig rich is also why it runs/idles rough especially when cold, smells like straight raw gas... I never experienced such a rough idle when I had the stock-untuned 747...

3.) Since I have driven around with the new PCM wired up, does this mean that I did wire it up correctly?

4.) How can the BLMs be so far off when the bin I'm using is so close to my combination?!?! (BJLH with a couple tweaks)

5.) Using that ADX I actually logged TWO errors, but only EGR failure was shown in the malfunction codes, what is up with the other one and why can't I see it?

Other than the myriad of problems I've been having, it seems as if the 427 does in fact have a more crisp throttle response, and generally run better/ more responsively when it's not trying to choke up from a pig rich idle.. Now if I could just iron it out elsewhere....

I'm going to post a log I took in hopes that somebody will take a look at it and educate me. Sorry it has a bit long of an idle period at the beginning.

Thanks to all you veteran tuners for helping me sort though this.

[Six_Shooter]

My Mantra:

"Don't trust numbers alone."

Does the exhaust seem rich?
Do the plugs show a rich condition?
Are you using a lot of fuel?
Is the timing correct?
Is the fuel pressure correct?

I tend to do initial tunes in open loop, usually with a Wide Band O2, to get fueling close, because the NBO2 can lie, especially if it's old and has been forced to run in excessivly rich conditions for an extended period.

[EagleMark]

Tried that ADX and it has the history tables but still nothing for monitors?

I think I might be on the track to getting somewhere.... I captured a log, and my BLMs were off as I expected for a basically stock tune, but some were like 90!!! How can this be so far off when the bin I'm using is so close to my combination?!?! I noticed during my log that I got an EGR error code so I will now disable that as I have long since trashed the EGR vavle...

QUESTIONS:

1.) How do you guys know which definition to use when there are so many of them for any given ECM?


2.) I would think that this thing running so pig rich is also why it runs/idles rough especially when cold, smells like straight raw gas... I never experienced such a rough idle when I had the stock-untuned 747...

3.) Since I have driven around with the new PCM wired up, does this mean that I did wire it up correctly?

4.) How can the BLMs be so far off when the bin I'm using is so close to my combination?!?! (BJLH with a couple tweaks)

5.) Using that ADX I actually logged TWO errors, but only EGR failure was shown in the malfunction codes, what is up with the other one and why can't I see it?

Other than the myriad of problems I've been having, it seems as if the 427 does in fact have a more crisp throttle response, and generally run better/ more responsively when it's not trying to choke up from a pig rich idle.. Now if I could just iron it out elsewhere....

I'm going to post a log I took in hopes that somebody will take a look at it and educate me. Sorry it has a bit long of an idle period at the beginning.

Thanks to all you veteran tuners for helping me sort though this.That's a lot of questions and will take a week to go through and learn all that, we will but I think you had a need to drive this?

BJLH is $0D and the ADX Dave W posted for you is correct. You are getting data, your monitors will work for whatever you want when you right click and choose something. History table shows BLM numbers whick will always be 128 when in open loop. I don't see any error codes yet so nothing ther is holding you up. Ah towards the end you got a code 32 EGR failure which was propbably the test, that you failed for running so bad or you don't have an EGR.

The only thing I can see in that log, other then not running to good at idle is idle BLM hitting 90? Since low BLM is 105 and your there a lot, how does it go to 90?

OK begining of log you say is idle, but it's in drive?

What motor? Did it run well before the conversion? What transmission?

In reading some of the last post I think you did not have a lot of time in $42 and now your in data overload? Stop worrying about all the data, there's way to much in $0D, most of which I wouldn't even know what to do with.

Closed loop says way rich. Why? Back to how did motor run before the conversion to new PCM? Do you know what fuel pressure is? Could you have done anything to create a vacuum leak? Could O2 sensor be bad? Or soaked with gas now? Have you pulled a spark plug? Does it look sooted black? Pull one, if does not look tan, pull another...

If you don't have an 4L60E trans and only a couple tweaks to PCM, then I'll bet you have every error code set that are not in the ADX you are using which is for engine, and has a few trans error codes, the trans ADX has many more.

[CDeeZ]

You know I noticed something that may be of significance. When I would go key on with the 747, I could hear the fuel pump prime for oh, I don't know, maybe 3-4 seconds... But now, with the PCM swapped, when I go key on, I hear the pump priming for like 10-11 seconds!!! I checked both wires pertaining to fuel pump in the conversion thread, Fuel Pump Relay GRN/WHT is on pin F6 where it should be. And I THINK the Fuel Pump Signal at B12 is right... Thing is, my wire is GREY, whereas the conversion thread says it should be TAN/WHT.... So I'm kind of forced to fly in the dark on that one....

Is there a coincidince that my fuel pump seems to be priming abnormally long, my last and only recorded BLM since swapping PCMs shows WAY rich, and while I haven't checked the plugs, the exhaust definetly smells stupidly rich.

[CDeeZ]

Yes I'm very interested in learning, but I do also need a driver!


Okay so I have to right click for that to work I see.. You'll have to forgive me, the laptop I use for datalogging is actually quite a POS, not very user friendly, its small, mouse pad and keyboard are hard to use, it's not exactly a performance powerhouse, the screen is dinky, etc. etc. but it's what I got to work with! I only use it for logging since it's such a piece, I switch to my desktop for editing bins, downloading files, reading/posting forums etc since it's much easier to use.. Having to use two machines makes things a little more tricky! My desktop that I use for tuning is actually a Macintosh with a partitioned hard-drive running OSX on one side and Win7 on the other for the tuning bit! Did I mention that I'm also not a fan of the way Microsoft changed the file structure in Win7 versus previous older versions? END RANT LOL


Yes, I have long, long since removed the EGR. I tuned it out on the 747... Now I have to do the same again.


As far as the BLM, I have absolutely no idea? I was hoping you could tell me. I think 90 is the lowest BLM I've ever seen/recorded/read about.


Beginning of log was idling in driveway, manual transmission equipped so shouldn't the PCM always assume the vehicle is in gear???


350 TBI, very mildly massaged, DD2000 estimated ~300-350HP ~400-450LB/FTTQ. Ran like a raped date before the conversion, my tune was far from perfect on the old 747, but it ran GOOD anyways, T56 6 speed manual transmission 2.66 1st .5 6th variant


Yes, I might very well be in data overload, which is what I was afraid of, but how else do you know until you just take the plunge.. I first got my chip burning equipment from Moates about four years ago, so I am experienced, but certainly have much to learn.


Again, before conversion I was always on the rich side, but it ran very good. I don't have a way to test the fuel pressure, I really should add a permanent gauge to the back of the injector pod. I never tested fuel pressure when running the 747, just worked on the VEs a little and I got a lot of the BLMS +/-3... When I rebuilt the throttle body I made the regulator adjustable and turned up the fuel pressure to an estimated ~14 PSI.....


No known vacuum leaks, 02 sensor replaced maybe 1 month ago, plugs fresh, haven't check recently but they were tan last time I did check them. I will try to check the plugs tomorrow. It's HOT here in Oklahoma so that is something I'm looking forward to ;)


No, no 4L60E here, just six speeds of manually shifted manliness in the form of the T56...


Let me ask this... EXACTLY which ADX should I use that has everything in it so that I CAN disable all error codes pertaining to the automatic that isn't there?? I know there are several posted around, but I'm confused on which one is the “most complete” or whatever.


This thing ran great before the PCM conversion.

I know using dave's BPW spreadsheet I'd calculate a BPW and drop that in, but where is the BPW in the 427 PCM? I feel like my issue is maybe something with the fueling? And why is the fuel pump priming so much longer now!?!?

[EagleMark]

Gray to Tan/White thing is a GM change, no sweat if your sure it's the right wire.

Not sure why the long prime? Some HD trucks did that to ensure a cool down of fuel when starting a very hot truck engine. But right now it's not your issue.

[dave w]

Long prime of 10 or 11 seconds is OK, stop thinking about that as a possible problem.

What I'd do:

Set the .bin to manual trans. Change the TBI injector flow from the stock setting of 61 to 65 to see if that new setting leans it out at idle. Caution, TBI injector flow of 65 is likely to make RPM's over 2400 a touch lean. Basically after I convert to a '427 PCM I use the trial and error method of setting the injector flow that gets most of the BLM's between 118 ~ 138 and then I fix the VE Tables.

dave w

[gregs78cam]

I know using dave's BPW spreadsheet I'd calculate a BPW and drop that in, but where is the BPW in the 427 PCM? I feel like my issue is maybe something with the fueling? And why is the fuel pump priming so much longer now!?!?

There is no BPW, or more correctly BPC - Base Pulse Constant, Only Injector Flowrate.

There is a location in the .bin to set the fuel pump prime duration. Under "Crank to Run Transition Parameters", "Maximum Time for Fuel Pump Running with No DRP - location 0x4958."

[JeepsAndGuns]

When I rebuilt the throttle body I made the regulator adjustable and turned up the fuel pressure to an estimated ~14 PSI.....

I wonder if this could be the problem? If you did not have a pressure gauge to set the pressure, mabey you have it high, and therefore the injectors are flowing more than what the pcm is expecting/programmed for, and making the bpw be off and run pig rich. Mabey it would be a real good idea to get a gauge and confirm the actual fuel pressure, so the correct injector flow rate can be entered into the bin.

[CDeeZ]

Well I ended up changing pins again and reinstalling the 747.. Having a toy to tinker with/learn on is especially difficult when that vehicle is also a daily driver :\

Thanks for the help anyway guys

[Six_Shooter]

Well I ended up changing pins again and reinstalling the 747.. Having a toy to tinker with/learn on is especially difficult when that vehicle is also a daily driver :\

Thanks for the help anyway guys

You should make an adapter harness, so that you can swap back and forth easily. That way you can work on the tune for the new ECM, while still having the stand by of the old ECM.

[CDeeZ]

I think I will do exactly that. I was going to do that originally, but decided to just try swapping pins. Time to spend some quality time with the soldering iron :)

[CDeeZ]

I made an adapter. Will post pics tomorrow

[CDeeZ]

2745274827492747

I need to get some more heatshrink and put it on the few remaining wires w/o it and it should be ready to go.

[JeepsAndGuns]

Looks like the one I made back when I was too chicken to jump in feet first.
Thing was kinda a PITA to make wasnt it?

http://img.photobucket.com/albums/v606/JeepsAndGuns/2011-10-02092120.jpg

[CDeeZ]

It was not hard to make at all, just a little bit time consuming. It helps if you have a helper who can hold the wires while you're soldering them.

I have made a couple runs around with the new 7427 PCM calling the shots, and I think after playing around with my injector flow I have finally got this PCM to behave in my setup. BLMs still say rich, but it's better now than it was the first time I tried to fire up the 7427 PCM.

I'm posting a .XLS spreadsheet with some BLMs I recorded today. It looks like I'm headed in the right direction, but I was hoping ya'll would check it out and give me your insight.

Taking daves advice, I've been messing around with the TBI injector flowrate under engine constants, and I have my injector flowrate set @ 69 lb/hr.

69 lb/hr is what the injector flowrate was set to when I collected this data during the datalog.

[dave w]

I use Running Average, which I think is more accurate data. I think history average is not very useful for tuning. The lower RPM's are Rich and Upper RPM's are just barely rich, time to adjust the VE tables. Post the .xdl log file, I'll play it back and offer suggestions.

dave w

[CDeeZ]

Awesome, thanks dave. I used BJLH.bin for a bin to start from. Here is my .xdl log from earlier today.

I don't know if this might also be of use, but here is the bin as I've tweaked it, and a .txt stating what I've done. I know TPRT makes it's own .txt edit log, but I prefer to take my own notes.

[EagleMark]

I use Running Average, which I think is more accurate data. I think history average is not very useful for tuning. The lower RPM's are Rich and Upper RPM's are just barely rich, time to adjust the VE tables. Post the .xdl log file, I'll play it back and offer suggestions.

dave wIf you start log after completly warmed up it takes out all the cold data you don't want. History average is usually an issue because by default it is set to 10 data counts, I change that to 100. Then compare History to Running and they are the same.

We're not all as good as you with Excel... :innocent2:

[RobertISaar]

depends on how long of logs you have.... running is the total since the cells were last cleared, history is the last x number of samples that belong to the cell. i get upwards of a few thousand in relatively short logs, depending on what i'm doing.

[dave w]

Awesome, thanks dave. I used BJLH.bin for a bin to start from. Here is my .xdl log from earlier today.

I don't know if this might also be of use, but here is the bin as I've tweaked it, and a .txt stating what I've done. I know TPRT makes it's own .txt edit log, but I prefer to take my own notes.

I have attached a VE Correction Spreadsheet (Excel .zip file) for the 7.14.12 log. The running average was used for the BLM's.

dave w

[CDeeZ]

Thanks for helping me out with this dave, it is much appreciated. Did you see anything in the log while playing it back that jumped out at you? Is my selected injector flowrate good to go since it's now VE time? I pasted my new VE tables from the spreadsheet into the tune, will give it a run tomorrow.

[dave w]

Thanks for helping me out with this dave, it is much appreciated. Did you see anything in the log while playing it back that jumped out at you? Is my selected injector flowrate good to go since it's now VE time? I pasted my new VE tables from the spreadsheet into the tune, will give it a run tomorrow.

I did not spend much time looking at the data log, I was thinking that the VE Fixer was the best bang for the time I could spend helping out. I think the injector flow is OK for now. The new VE tables should help. Let me know how it goes.

dave w

[CDeeZ]

Thanks again. I have to go do some driving for work today so I will hopefully get a nice sizeable log of data to work with for tweaking the VEs a little bit more.

One thing I noticed playing the log back, a code 24 "transmission output speed low" was recorded... I NEVER got a code 24 with the old 747 ECM. Any ideas here?

[Six_Shooter]

Are your logs showing vehicle speed?

[CDeeZ]

Yeah, the logs are showing vehicle speed. My speedometer is a little bit off, I need to play with recalibrating my DRAC/VSSB, but the speedo works and PCM is seeing something coming in from the VSS.

Under "Speed and RPM Limiter Parameters" on the parameter category tree there are several things I have a question about.

QUESTIONS:
1.)I want to totally disable the MPH speed limiter. I have "MPH to Resume Fueling" set to ZERO MPH, and "MPH to Enter Fuel Cut Off" is set to 255 MPH. Is this going to disable the MPH limiter the way I have it configured?

2.) ALSO under the "Speed and RPM Limiter Parameters" category are two constants I just discovered: "RPM to Enter Fuel Cut Off if Transmission Error" and "RPM to Resume Fueling if Transmission Error". These are set at 4300 RPM and 3850 RPM, respectively. Now getting on the on ramp today I was winding the engine up to 4K+ RPM to try and populate those higher RPM cells with data, when I felt the engine cut out for a moment then come right back to life as if it were going lean up top... I'm almost CERTAIN that these two little parameters are responsible for the cut-out I experienced earlier, especially since I've got a code 24 showing.
I'm ASSUMING these limiters are there to work with the automatic transmission that I DON'T have.

I'm going to set both of these constants to the highest possible RPM to get rid of them, this is okay, correct?

Basically I only want a plain old-RPM limiter, if even that much! No limiter on MPH, and no limiter on RPM when the PCM thinks the automatic(that I don't have) is having issues.

Thanks ya'll!

[RobertISaar]

currently, you would have to hit 255MPH, then roll down to 0MPH, before the speed limiter is disabled. change the 0 to 254.

to test that those ARE the items reponsible, lower them considerably, then see if it happens again. otherwise, raise to maximum.

[CDeeZ]

Thanks Robert,

I will change the 0 to 254, even though I won't hit the 255MPH mark to enter fuel cut off, not today at least :)

I'm going to test those items and see if they are in fact responsible. I'm 99% sure that's what I experienced earlier, b/c the RPM at which the engine cut out was exactly what that constant was set to! I will report back after I know something.

[CDeeZ]

I lowered those values to around 3K RPM and tested, they were in fact the cause. I've set them as high as they'll go now.

I still get code 24.....

I swapped gauges recently, from the "moonie" (88-90 C/K) style gauges to the later style cluster with needles (91-94 C/K). Everything works with the cluster, but at random intervals the speedo will jump up to some MPH much higher than actual speed the vechile is traveling. I wonder if this could be causing that error? All wires were soldered (like always) and everything else with the cluster works, but I wonder if its related to my code 24 issue?

What would be the benefit, if any, if I were to disable that error code in TunerPro so that it cannot be set by the PCM?

[CDeeZ]

What do you guys think I should do about the code 24? I thought about unchecking the box for that error code in the bin inTunerPro so that it cannot be set and stored as an error.

[gregs78cam]

I personally would try to figure out why the speedo is jumping, and remedy that, which will also eliminate the error code. It sounds like your twisted wire pair from the sensor are picking up a stray spike. Might check that the wires are twisted together along their entire length. When soldering those I usually go as far as to remove them from connector, solder, shrink, and re-twist them right up the connector.

[CDeeZ]

Thanks. I will check the twisted wires for the VSS, see if I find anything there. The older style gauges never had this speedo issue and the VSS and wiring for it have remained unchanged since. You think that it sounds like a spike being picked up by the VSS? It's been a few days since I swapped gauges, but IIRC, the DRAC itself has both VSS wires going into it (or out of it depending on how you look at it) and I know that when I installed the newer DRAC with the newer gauges, I didn't twist the VSS wires as they were coming out of the DRAC, didn't think I needed to. They should be twisted up everywhere else though. Maybe the VSS wires near the DRAC are picking up electromagnetic interference from something else in the dash.


I was looking at the only two known manual bins for '7427, BHDC and BMHK and BOTH of these bins have error 24 disabled! It appears as if code 24 – low transmission output speed is something that pertains to E-trannys, and not stick shifts.


On the 747 to 427 conversion thread it is said: “output speed not from DRAC set”. What exactly does this mean? I believe I've read that this PCM can take VSS signal with or without DRAC, so which one is better? Right now I've got a DRAC in the mix (obviously). What would be the point or advantage to bypassing the DRAC and feeding the VSS directly into the PCM? How is this done? I have a 40 PPR reluctor wheel in my transmission if that matters.

[EagleMark]

The manual bins are from $0E and a 4L80E trans with 2 speed sensors, not $0D for 4L60E. Only need DRAC for speedo, cruise and ABS

[CDeeZ]

Yes those bins use $0E mask, but I thought that BMHK and BHDC were for 5 speeds & not 4L80s, since it lists that in the full bin name in the fileman?

And by the way Mark, correct me if I'm wrong here, but didn't you guys end up running one of these binaries, either the BMHK or BHDC for your sons '427 $0E?

I'm going to try an experiment: copy all my changes so far from the bin I've been working with ($0D-BJLH.bin) fuel tables, injector constant, cylinder volume etc. etc. and give the $0E a whirl with either BMHK or BHDC. Maybe it will be better?

[EagleMark]

We did use an $0E maual bin and Code 24 is off.

[CDeeZ]

I gave a 454-5spd bin a try after copying my VE and spark tables, spark biases, injector flowrates etc. It didn't seem to run right so rather than mess with that I reverted back to the BJLH 5.7/60e bin. I also have turned off code 24, at least for the time being.

Today when I had some free time I took the dash apart and removed the gauges. I took the two wires for VSS, hi and low speed signals, and twisted them up from the DRAC all the way to the wiring harness as it disappears into the dash. I also checked the VSS wires under the vehicle and they seem to be sufficiently twisted to keep out unwanted electromagnetic exposure, RFI or whatever we should call it.

On a side note, while inspecting the VSS wires under the truck, I found what appears to be a broken transmission mount on my T56. Either that, or it has come unbolted somehow. I think this tranny mount has been rattling for some time. I don't know how I didn't discover it sooner than I did. Probably because it's been so hot for a while now that I don't wanna crawl on the scorching pavement under any vehicle.

It was 104* F in the SHADE today here in the OK :yikes:

[EagleMark]

You really shouldn't be playing with Spark Bias from mask to mask or even bin to bin in same mask! For example using Spark Bias from $42 5.7L to $42 7.4L you are now off by 9.8 degrees in main table. Only another 100 possibilities to think of...

Just looked at $0E and compared 5.7L to 7.4L and same thing, 9.8 degrees off in main table, now how does that effect coolant temp spark, PE spark, Decel Spark, DFCO etc...? Way to much for me to rule out or attempt to work with...

Weather here today was 80's and thunder storms, feels like Louisiana or Florida (no big bugs yet, but first time I have ever seen slugs cover the sidewalks at night?). We never have thunder storms this time of year? Watch the news and or grain belt is in horrible drought? Ha! Our farms are still under water. Still cutting grass twice a week without watering.

[CDeeZ]

I thought if I copied the spark tables AND the biases it would be ok. I though the place one might get into trouble is if you copied the spark tables but not the biases! No matter, I went back to the 5.7/60e bin I've been working with and I'll probably continue to use that since I've had the best luck with it.

I wish it was 80's and stormy here. Yeah it is incredibly dry here, needing some rain pretty bad. It's been so hot and dry the grass hasn't been growing all that fast. I guess extreme heat and lack of water will do that.

[dave w]

I've adopted the practice of using a starter .bin that is close to the intended application as possible!:thumbsup: I understand that is some applications the "close" starter .bin file is not going to be very close.:mad1: Usually there are settings with Deceleration Fuel Cut Off (DFCO), injector voltage offsets, and choke settings that WILL cause some serious CHALLENGES if the starter .bin is not very close! For me the easy part is the spark and fuel tables, but figuring out how to set DFCO so a consistent exhaust backfire will not blow out a muffler is not an easy fix!:mad1: To date, the most challenging "Tunes" I've done have been with SBC 383's!

dave w

[CDeeZ]

Yeah that makes perfect sense. I actually have a a backup copy of my base bin that I started with, saved as "starter.bin" so I know that's the bin to revert back to if I make some changes that don't pan out, plus that bin already has my basic settings adjusted : Initial Spark, Injector-LBS/HR, EGR-disabled, etc. etc.

It sounds like you might be speaking from experience on blowing out mufflers? Yikes! I can only begin to imagine how difficult it would be to tune a 383 SBC since the "closest" thing would be some kind of 350.bin
and even that I'd guess would be pretty far off due to the significant difference in engine displacement.

By the way dave, since you brought it up, what specifically are some of the challenges you have faced when tuning for a 383? Just wondering.

I've kicked around the idea of building up a 383TBI to replace my 350 TBI, but the 350 seems to have tons of life left in it (thankfully!) so even that wouldn't be any time soon likely.
As cool as a 383 would be, I think when the time comes for a replacement for the TBI-350 I should finally drop in my LQ4 :rockon:

[dave w]

By the way dave, since you brought it up, what specifically are some of the challenges you have faced when tuning for a 383? Just wondering.

The quick answer, EVERYTHING! Choke, DFCO, AE, PE, 4WD LO (when equipped) and Emissions (when required) are the real time consuming challenges.

dave w