350 Vortec wi th 454 TBI running pig rich

[rsicard]

As a relative newbie, need some advice. Converted '98 350 Vortec to TBI using 454 throttle body, 4 barrel intake and adapter. Have several injectors from 305, 350 and 454 TBIs. Purchased Cop Car injectors that are NOT marked supposedly 65 pph. Keep running into the same situation wherein the engine runs pig rich at idle. Fuel pressure at present is 14 psi. Just switched to 350 injectors and still runs pig rich. Installed adjustable pressure regulator and have it at lowest pressure setting. Still runs rich.

Found that Oring sizes and fit are critical in the fuel portion of the TBI. Got the wrong size, wrong fit and it hydraulically LOCKED the engine. Pulled all the spark plugs and rotated with starter. Got a gasoline bath. Tried to dry out plugs and reinstalled. Still misfiring and running pig rich. Went to the auto parts store for new spark plugs. Need to get these installed and try again.

Advise needed for this situation.

[Chewy1576]

I just put 454 injectors (80 lb/hr) over my TBI 383. Had to update the BPW/BPC for the displacement, injector flow, and fuel pressure from 135 to 96. I also deleted the EGR. After a few datalogs and updates to the VE table it is running very well.

[rsicard]

I just put 454 injectors (80 lb/hr) over my TBI 383. Had to update the BPW/BPC for the displacement, injector flow, and fuel pressure from 135 to 96. I also deleted the EGR. After a few datalogs and updates to the VE table it is running very well.

Did you replace the electric fuel pump with one that could achieve higher pressure? What was the fuel pressure set at? Don't understand fuel pressure 135 to 96. How was the EGR deleted. Did you emulate to update the VE tables? Was a wideband O2 sensor/display hooked up when modifying the VE tables? Please advise. Thanks.

[BLG355]

It sounds like you have too much fuel. Your VE tables will need updated, but you need to get something close for it to work off of. Are you sure you don't have a pinched return line or something? Does it lean out when it warms up and gets into closed loop? Can you post a datalog?

BLG

[rsicard]

It sounds like you have too much fuel. Your VE tables will need updated, but you need to get something close for it to work off of. Are you sure you don't have a pinched return line or something? Does it lean out when it warms up and gets into closed loop? Can you post a datalog?

BLG

Would be pleased to attach a datalog. As a relative newbie, learning how to tune the hard way. Get little bits and pieces. Yet it may all add up in the end. The engine is a 1998 350 Vortec with a 4 barrel manifold on top of which is a 454 throttle body on an adapter. It is on a run-in stand right now. Will check to see if the fuel return line is clear. Using export Vortec 5.7L TBI binary file. Fuel Pressure is at 12-14 psi. Purchased supposed 65 pph injectors off of Ebay. Came unmarked look refurbished. Hooked up Innovate LM-1 Wide Band AFR. Runs 10 AFR at idle. Occasionally, leans out to 17 AFR and almost quits at idle then goes back to rich AFR. Installed used 350 (slightly smaller) injectors, same rich AFR results.

Thinks maybe it is the MemCal. Will pull the MemCal from the 1995 Chev C1500 pickup, and try, that the Vortec on the engine stand is to be installed in to replace the oil burner in the pickup now.

Seems as though it is in Limp Home Mode (LHM) all the time??? Please advise. Thanks.

[Chewy1576]

Did you replace the electric fuel pump with one that could achieve higher pressure? What was the fuel pressure set at? Don't understand fuel pressure 135 to 96. How was the EGR deleted. Did you emulate to update the VE tables? Was a wideband O2 sensor/display hooked up when modifying the VE tables? Please advise. Thanks.

Yes I installed an EP381 fuel pump and 18 psi spring in the regulator to achieve a higher pressure. It was the Base Pulse Width that I changed from 135 to 96. 135 was the value from the factory with 350 cubic inch engine, 56 #/hr injectors, and 13 psi fuel pressure. I'm now at 383 cubic inches, 80 #/hr injectors, and 18 psi fuel pressure. There is a spreadsheet Dave W created in another post that will do this calculation for you. To delete the EGR I sandwiched an aluminum plate between the valve and the intake to seal the port, then increased the EGR enable RPM to its maximum value. Dave W's spreadsheet will also update VE tables if you can input your current table and average BLM values from a datalog. Update and log a few times and it gets very close to running efficiently. I don't have a wideband O2, just a new Bosch replacement sensor.

[rsicard]

Yes I installed an EP381 fuel pump and 18 psi spring in the regulator to achieve a higher pressure. It was the Base Pulse Width that I changed from 135 to 96. 135 was the value from the factory with 350 cubic inch engine, 56 #/hr injectors, and 13 psi fuel pressure. I'm now at 383 cubic inches, 80 #/hr injectors, and 18 psi fuel pressure. There is a spreadsheet Dave W created in another post that will do this calculation for you. To delete the EGR I sandwiched an aluminum plate between the valve and the intake to seal the port, then increased the EGR enable RPM to its maximum value. Dave W's spreadsheet will also update VE tables if you can input your current table and average BLM values from a datalog. Update and log a few times and it gets very close to running efficiently. I don't have a wideband O2, just a new Bosch replacement sensor.

Thanks much for the reply. You have a 747 ECM, I have a 7427 ECM. Was the base pulse width setting item in the Scalars, Flags or Tables? Guessing the Scalars. Trying to interpret which item should be changed for base pulse width in the long list of TunerPro for 7427 ECM which I have. Understand what Dave W. has done with the spreadsheets. Just trying to lean out the fuel some as a first step.

[Chewy1576]

I'm not 100% sure but I think it's call Base Pulse Constant in the 7427 ECM. For me, the Base Pulse Width was one of the first scalar values in the parameter list.

[delcowizzid]

injector flow rate TBI in your xdf.
dave-w did help someone with 10 degrees missing commanded v's actual timing think his fix was zeroing the altitude spark bias in the constants

[rsicard]

injector flow rate TBI in your xdf.
dave-w did help someone with 10 degrees missing commanded v's actual timing think his fix was zeroing the altitude spark bias in the constants

Try to understand what "injector flow rate TBI in your xdf" is supposed to mean. "Altitude spark bias" don't understand. Please advise. Thanks.

[rsicard]

injector flow rate TBI in your xdf.
dave-w did help someone with 10 degrees missing commanded v's actual timing think his fix was zeroing the altitude spark bias in the constants

The reader has NO idea what the writer is trying to convey. Have no idea what is in the writers brain.

[rsicard]

injector flow rate TBI in your xdf.
dave-w did help someone with 10 degrees missing commanded v's actual timing think his fix was zeroing the altitude spark bias in the constants

I am certain that you are trying to help, yet don't understand the meaning of what you have said. Need to spell out what is in your thoughts.

[brian617]

rsicard,

With all due respect, stop posting and start searching and reading. You have started so many post, yet not followed through with anyones advice. Go here http://www.gearhead-efi.com/Fuel-Injection/showthread.php?29-FAQ-on-EFI-Conversion-Links-Troubleshooting-Error-Codes! and read all the sticky links. When your'e done, read them all again. Same here http://www.gearhead-efi.com/Fuel-Injection/showthread.php?3255-General-EFI-information-and-links-AKA-quot-FAQ-quot

There are hour after hour of great reading information in those links.

[rsicard]

rsicard,

With all due respect, stop posting and start searching and reading. You have started so many post, yet not followed through with anyones advice. Go here http://www.gearhead-efi.com/Fuel-Injection/showthread.php?29-FAQ-on-EFI-Conversion-Links-Troubleshooting-Error-Codes! and read all the sticky links. When your'e done, read them all again. Same here http://www.gearhead-efi.com/Fuel-Injection/showthread.php?3255-General-EFI-information-and-links-AKA-quot-FAQ-quot



There are hour after hour of great reading information in those links.

Brian617: Understand what you are saying. Have read at least 1/2 of what you have provided links for. Have spent many an hour reading through the materials. Still have open questions. Understand if the guys on here are getting tired of seeing my name. But after not achieving an objective, there is much more to do. I will go off and read the other link you posted and gather a compendium of what was posted. Maybe it will provide more insight. So the responses have come in little bits and pieces that do not form a bigger complete picture in the mind. Maybe forming a compendium of the other link will do the job. Every person uses their own terminology. Lots of TLAs. Again, the reader does not know what is in the writers mind unless the writer spells it all out the picture in his mind. Find this to be a very common problem leading to misunderstandings and taking the wrong path forward. See this every day.

Getting really tired and frustrated of seemly getting NOWHERE. Only on about the 7th or 8th run on the engine stand. Got a whole collection of injectors and regulator springs. No positive way to measure their performance. Don't have automated test equipment to test the ECMs for quality of performance. Worked in engineering on the B2 bomber 750 shaft Horse Power Aux Power Unit (APU) Electronics Control Unit (ECU). Characterized the ECU and formed Lotus 123 spread sheet of input and outputs with limits and tested the Line Replaceable Units (LRUs) in 45 seconds with embedded 8088 microprocessor on Std buss rack. Worked like gang busters. Lots of experience in Aerospace Electronics.

[DOCBAWRENCHTURNER]

rsicard- I have been in the same boat with the engine running pig rich. the BPW is in the scalars. I believe that there is a calculator/excel file somewhere to help with this. I ended up telling the PCM that my injectors are larger than what it has in it due to my increased fuel pressure. Also the number your changing is a pcm based number, it will be somewhere around 10 and probably a decimal. You also need to make sure that you IAC is set to where it needs to be (there is a write up about this). I believe Mark said he aimed for ~20 counts.

edit... I understand your frustration that after 7-8 tries you haven't been able to see any progress, keep in mind that most people here have tried 10-20 times a day. There is a method to this madness, but the learning curve is steep. I have a 96 Vortec engine in a 95 pickup running TBI, similar issues, but we all have to work one step at a time.

[rsicard]

rsicard- I have been in the same boat with the engine running pig rich. the BPW is in the scalars. I believe that there is a calculator/excel file somewhere to help with this. I ended up telling the PCM that my injectors are larger than what it has in it due to my increased fuel pressure. Also the number your changing is a pcm based number, it will be somewhere around 10 and probably a decimal. You also need to make sure that you IAC is set to where it needs to be (there is a write up about this). I believe Mark said he aimed for ~20 counts.

edit... I understand your frustration that after 7-8 tries you haven't been able to see any progress, keep in mind that most people here have tried 10-20 times a day. There is a method to this madness, but the learning curve is steep. I have a 96 Vortec engine in a 95 pickup running TBI, similar issues, but we all have to work one step at a time.

DOCBAWRENCHTURNER: Really appreciate your post. I am retired and getting older by the day. Will keep looking for BPW adjustments in TunerPro. Tried several regulator springs and the lowest pressure that can be achieved is 12-14 psi. Will try the 7.4L injectors and bump up the fuel pressure to see what happens. Thinking about putting in an external fuel regulator, referenced to manifold vacuum, to adjust pressure easily. If I can get SOMEWHERE close to where it should be, then will tune VE and use Dave W. spreadsheet stuff to get closer to 14.7 AFR.

Sure would be nice to have a checklist to go by for setting these things up. Just got done forming another lengthy document of the links provided by Brian617. Have seen this stuff all before. Still have open questions. Likely, people like Dave W. are tired of responding to my questions. Sure would like to get one of them on the telephone and form a checklist in my brain. Then I would write it down. Can always bite the bullet and spend multi-thousands of dollars for a self learning sequential port fuel injection system. But I am retired and on a fixed income. Chose a 1995 pickup because parts are cheaper than the newer models. Want this one to last until I pass on. Already have a Monster rebuilt 4L60E and latest Hughes Torque converter ready to go behind the Vortec. Now if I could only get the Vortec running properly. Spent enough money already.

[brian617]

There is no BPW constant in the 7427, only Injector Flow Rate, but as I mention before you cannot change it until you've settled on a injector/fuel pressure combo. In one of my replys I insisted you quit fumbling with different injectors and fuel pressure and just pick the combo you need for your HP requirement, even gave you the link to the injector calculator.

First, what HP number is your engine combo good for 350hp? If so 350hp with a BSFC Brake Specific Fuel Consumption of .475 at 85% IDC Injector Duty Cycle says you need 98 PPH Pounds Per Hour of fuel. Now you take you 65 PPH @ 13PSI 350 injectors and you need 30+ PSI of fuel pressure to ahcive this goal. or you could use BBC 80PPH @ 13psi injectors you need 20psi to get there. http://www.witchhunter.com/injectorcalc1.php

Once you get that set you must make the change to the Injector Flow Rate in your .BIN, but dont expect it to run great strait out of the box. This is were the changes in the VE table must be made.

[sturgillbd]

Ok... In $0D, there is simply a injector PPH setting. Open up Tuner Pro and switch to parameter category view. One screenshot below will show you the injector size setting and the another screenshot is thelocation of the VE tables. If you have the 65 PPH injectors in the TBI, set it to 65 instead of the default 61. Where you have increased your pressure you will have to calculate the new flow based on your new pressure. The idle VE table is also pictured and that is where you adjust the Idle VE. You have to learn to crawl before you learn to run. There are many documents on here and on the web that describe tuning these systems. Some describe using WinALDL for logging such as this : http://www.gmcmidwestclassics.org/Web%20pages/Tuning%20the%20TBI.pdf but it is for tuning a 1227747 ecm on a motorhome. The same basic principles apply for the 16197427 but the 7427 is a more complicated controller. If you switch to parameter view, Tunerpro groups the tables, scalars in a more readable format for me. When you first dive into tuning, you feel like a lost ball in high weeds. Take your time and read. Open the bin, look through the parameters. The parameters for $0D are well documented. If you put the mouse pointer over a parameter, it will have a floating window pop up with the description of what it does. Once you know what your injectors are flowing at your set pressure, put that into the injector size in PPH. I am going to attach 3 screenshots and maybe this will help you get started.

[rsicard]

Ok... In $0D, there is simply a injector PPH setting. Open up Tuner Pro and switch to parameter category view. One screenshot below will show you the injector size setting and the another screenshot is thelocation of the VE tables. If you have the 65 PPH injectors in the TBI, set it to 65 instead of the default 61. Where you have increased your pressure you will have to calculate the new flow based on your new pressure. The idle VE table is also pictured and that is where you adjust the Idle VE. You have to learn to crawl before you learn to run. There are many documents on here and on the web that describe tuning these systems. Some describe using WinALDL for logging such as this : http://www.gmcmidwestclassics.org/Web%20pages/Tuning%20the%20TBI.pdf but it is for tuning a 1227747 ecm on a motorhome. The same basic principles apply for the 16197427 but the 7427 is a more complicated controller. If you switch to parameter view, Tunerpro groups the tables, scalars in a more readable format for me. When you first dive into tuning, you feel like a lost ball in high weeds. Take your time and read. Open the bin, look through the parameters. The parameters for $0D are well documented. If you put the mouse pointer over a parameter, it will have a floating window pop up with the description of what it does. Once you know what your injectors are flowing at your set pressure, put that into the injector size in PPH. I am going to attach 3 screenshots and maybe this will help you get started.

Strugillbd: By providing images of the TunerPro screens for 7427, you are hitting the ball out of the park. Really good stuff. This is the stuff that can really be used. There are SO MANY selections in the TunerPro Constants, Flags and Tables it can easily get confusing. The way you present it with images, get right to the point clearly. A picture is worth a thousand words.

Before I can use what you have posted, with 61 or 65 pph injectors and 12-14 psi, the 350 Vortec is running PIG RICH Wide Band AFR=10.x:1. Is there an indicator when running in Limp Home Mode? I suspect that the appropriate MemCal must be used. I will have to get one out of the 1995 Chev C1500 pickup and use it. Perhaps that will fix the PIG RICH situation. Don't know how many different MemCals there are or what effect the different one have. Giving thought to using the 7.4L injectors and adjusting fuel pressure AFTER getting the PIG RICH situation under control.

Attached is an image file of TunerPro and the constant set for TBI.

[rsicard]

There is no BPW constant in the 7427, only Injector Flow Rate, but as I mention before you cannot change it until you've settled on a injector/fuel pressure combo. In one of my replys I insisted you quit fumbling with different injectors and fuel pressure and just pick the combo you need for your HP requirement, even gave you the link to the injector calculator.

First, what HP number is your engine combo good for 350hp? If so 350hp with a BSFC Brake Specific Fuel Consumption of .475 at 85% IDC Injector Duty Cycle says you need 98 PPH Pounds Per Hour of fuel. Now you take you 65 PPH @ 13PSI 350 injectors and you need 30+ PSI of fuel pressure to ahcive this goal. or you could use BBC 80PPH @ 13psi injectors you need 20psi to get there. http://www.witchhunter.com/injectorcalc1.php

Once you get that set you must make the change to the Injector Flow Rate in your .BIN, but dont expect it to run great strait out of the box. This is were the changes in the VE table must be made.

Brian617: First have to fix the PIG RICH running situation. With 61 or 65 pph injectors and 12-14 psi fuel pressure, it runs Wide Band AFR 10.x:1. Kicks out black smoke it so rich. The 7.4L 30 psi injectors appear to be the way to go. The higher the pressure used with the injectors, the better the atomization of fuel. Better to use the 30 psi 7.4L '94-'95 injectors and dial in the fuel pressure to get it in the ball park of where the AFR should be. Then tune VE tables using Dave W. spreadsheet process. Suspect that the unknown MemCal I am using, may be causing the PIG RICH situation. Will use the one from my 1995 5.7L 350 engine using 16197427 ECU but will change out the Flash memory chip with a Moates adapter.

[sturgillbd]

Before we go into the bin, can you do us all a favor and take a picture of your tbi adapter? I want to see what you are using. There are some out there that are notorious for vacuum leaks. If it is the 1/4" steel plate or a thin aluminum plate, do the TBI mounting bolts protrude through it when the throttle body is mounted to it? If so, the bolts may be causing part of your issue.

[sturgillbd]

What was the 4 letter code on the memcal you were using?

[zuk1972]

I found this when I first started my vortec tune .
http://gearhead-efi.com/gearhead-efi/moates/1%20Moates%20Fileman/2)%20Custom%20Modified%20Binaries/mikes%20vortec%20tbi%20chip%2029.txt

The ve table got the idle /near idle richness in check -the ve table was a great starting point for me personally .Mine was black smoke rich at first .

[rsicard]

Before we go into the bin, can you do us all a favor and take a picture of your tbi adapter? I want to see what you are using. There are some out there that are notorious for vacuum leaks. If it is the 1/4" steel plate or a thin aluminum plate, do the TBI mounting bolts protrude through it when the throttle body is mounted to it? If so, the bolts may be causing part of your issue.

Right now it is dark outside. Since you are in Stone Gap VA, you are 3 hours later than we. Will take the pictures of the TBI adapter and 4 barrel manifold and post them. The adapter is 1/4" steel and I hogged it out to 2" bore like are on the 7.4L TBI. Also hogged out the 4 barrel manifold to also accomodate the 2" bores. Need take it apart to photo, and also study carefully for leaks..Just thought about it, have not "T"eed into the MAP sensor hose to see what the vacuum value is. Purchased a new MAP sensor from Oreilly Auto Parts. It is a BWD made part. Made a bracket for it to Vortec 4 barrel intake. Just pulled the ECU from the stock 1995 Chev C1500 pickup and ran the Vortec on it also just as it came out of the pickup. Still runs PIG RICH. Now suspect the MAP sensor may be getting fooled by a vacuum leak and causing the rich running condition???

I suspect that you are still employed and working approx 8 to 5. Will have the photos posted for you.

[rsicard]

What was the 4 letter code on the memcal you were using?

Will get the 4 letter code of the memcals being used and post. Thanks ever so much for your patience.

[rsicard]

I found this when I first started my vortec tune .
http://gearhead-efi.com/gearhead-efi/moates/1%20Moates%20Fileman/2)%20Custom%20Modified%20Binaries/mikes%20vortec%20tbi%20chip%2029.txt

The ve table got the idle /near idle richness in check -the ve table was a great starting point for me personally .Mine was black smoke rich at first .

Many thanks for the post.

[rsicard]

Before we go into the bin, can you do us all a favor and take a picture of your tbi adapter? I want to see what you are using. There are some out there that are notorious for vacuum leaks. If it is the 1/4" steel plate or a thin aluminum plate, do the TBI mounting bolts protrude through it when the throttle body is mounted to it? If so, the bolts may be causing part of your issue.

Found the vacuum leak. Took the throttle body (TB) and adapter plate off an cleaned. Purchase new TB gasket and new 4 barrel 4150 gasket. Sealed both of them with Loctite 509 sealer. Ran the engine and it appears to be running fine. Need another run with TunerPro. Will have to hook up Innovate LM-1 Wide Band O2 to APU1 and record Wide Band AFR with other parameters.

Attached are photos of the TB and adapter plate as requested.

[sturgillbd]

Thats good news. Its impossible to tune around a vacuum leak. Neat bracket you fabricated to take care of the throttle blade adjustment. Hopefully you are well on your way now.

[rsicard]

Thats good news. Its impossible to tune around a vacuum leak. Neat bracket you fabricated to take care of the throttle blade adjustment. Hopefully you are well on your way now.

The engine is running better. There is still something wrong with the ignition timing. A timing light on the balancer says zero to 10 degrees advanced. The TunerPro screen says something totally different. Need help with the ignition timing. Also the IAC comes up with a fault. Don't yet know what that is about. Log file attached.

[sturgillbd]

Will play your log in tunerpro and have a look

[sturgillbd]

Your throttle blades need to close more. Adjust your bolt to where it allows the blades to close more. You still are idling above the commanded idle rpm. The IAC is going to 0 counts at idle. That is your IAC fault. If you are positive you no longer have vacuum leaks, you will have to start adjusting your idle VE table. Your BLMs are at 90 in most places. Your bin is set to allow a minimum BLM of 90. You may look at the text file that zuk1972 posted the link to. You have to look at the VE table in the text file carefully because the taableis layed out backwars to what you will see in the bin for BJYL. I would get the tuning spread sheet and fill in the running average from the datalog you just posted and follow the explaination in this thread. http://www.gearhead-efi.com/Fuel-Injection/showthread.php?1895-Adjusting-VE-Fueling&

What are the specs on the cam you are using in this engine?

[delcowizzid]

yes the iac is maxed needs throttle blades closed.where did the ecu originate from did it come with the TBI unit .with the writing on the top would allmost look like its maybe been modified for multi point injection .wording looks like injector driver mod and netres jumper on the memcal

[sturgillbd]

I didn't see that picture when I looked last night. I viewed the pics from my phone and missed that. If the sense resistors have been jumped, it will be operating the injectors in saturated mode. Rsicard, Pull cover off of PCM and blue cover off memcal. Send pics of the internals.

[rsicard]

Your throttle blades need to close more. Adjust your bolt to where it allows the blades to close more. You still are idling above the commanded idle rpm. The IAC is going to 0 counts at idle. That is your IAC fault. If you are positive you no longer have vacuum leaks, you will have to start adjusting your idle VE table. Your BLMs are at 90 in most places. Your bin is set to allow a minimum BLM of 90. You may look at the text file that zuk1972 posted the link to. You have to look at the VE table in the text file carefully because the taableis layed out backwars to what you will see in the bin for BJYL. I would get the tuning spread sheet and fill in the running average from the datalog you just posted and follow the explaination in this thread. http://www.gearhead-efi.com/Fuel-Injection/showthread.php?1895-Adjusting-VE-Fueling&

What are the specs on the cam you are using in this engine?

The camshaft being used is the LT-4 Hot Cam. Installed it and also installed new Crane Cams valve springs on the Vortec heads. Specs as follows. Understand what needs to be done to the VE tables. First need to get the ignition timing situation under control. What the ECU is commanding for timing has no relationship to what is being strobed on the balancer. Need help with that.

LT-4 Hot Cam Specs

Hot Camshaft (P/N 24502586) Specifications

Intake Exhaust
Lobe Lift 0.328” 0.328”

Valve Lift
@ 1.5 ratio 0.492” 0.492”
@ 1.6 ratio 0.525” 0.525”

Duration

@lash point 279° 287
@0.006 cam 272 281
@0.050 cam lift 210° 228°

Lobe Centerline 109° 115°

Lobe Separation 112°

[rsicard]

I didn't see that picture when I looked last night. I viewed the pics from my phone and missed that. If the sense resistors have been jumped, it will be operating the injectors in saturated mode. Rsicard, Pull cover off of PCM and blue cover off memcal. Send pics of the internals.

Using the ECU from a 1994 K2500 suburban that had the 454 bored and stroked to 489 cu in and Edelbrock conversion to batch port injection via the 16197427 ECU and Edelbrock binary chip. Performed the MemCal and sense resistor mods, as directed, and the engine ran poorly. Backed out the MemCal mod, left the sense resistors jumpered, then the engine ran as before.

Will remove the jumpers and open up the MemCal and take pictures. Not sure what is being looked for. Need to get the ignition timing situation figured out also. Please advise. Thanks.

[rsicard]

yes the iac is maxed needs throttle blades closed.where did the ecu originate from did it come with the TBI unit .with the writing on the top would allmost look like its maybe been modified for multi point injection .wording looks like injector driver mod and netres jumper on the memcal

ECU came from 1994 7.4L Suburban modded with Edelbrock batch port injection intake manifold. Need to remove jumpers, then use ECU as test subject on 350 Vortec with appropriate binary chip.

[sturgillbd]

On the pfi mod, most people jumper two pins in the memcal to convert from tbi to pfi. It changes the firing strategy on the injectors from tbi to pfi. There is a thread or two on this board concerning the mod. I am using my phone at the moment and my lunch break is about over. Hopefully the mod in the pcm is just jumpers soldered over the sense resistors.

[rsicard]

On the pfi mod, most people jumper two pins in the memcal to convert from tbi to pfi. It changes the firing strategy on the injectors from tbi to pfi. There is a thread or two on this board concerning the mod. I am using my phone at the moment and my lunch break is about over. Hopefully the mod in the pcm is just jumpers soldered over the sense resistors.

You have been the one most helpful. Greatly appreciate that. Do not want to interfere with your employment to make money. The '94 Sub and '95 pickup are two different projects. Using assets from '94 to test 350 Vortec destined for '95 pickup which at present has an oil burner 350 engine. As long as I had the LT-4 Hot Cam, installed it and new valve springs to get even better performance out of the 350 Vortec which has GOOD compression and GOOD leakdown numbers. Priority now is to get the ignition timing situation under control on the 350 Vortec using '94 sub ECU and Vortec binary chip. Once that is sorted out, then get into fixing IAC situation and tuning the VE tables. Please advise. Thanks.

[sturgillbd]

Take off the jumpers from the resistors in the ECM. I would run the engine and get it to operating temp. I would start a datalog and try to fill in as many of the cells in the history table as I could for near idle. I would then run the data through the spreadsheet to lean it out. It may take more than one datalog to do this. You will only be able to partially tune near idle considering you have no load on the engine with it running on a test stand. With vortec heads, the spark table will have to be modified because BJYL was a calibration for a tbi headed engine. There are vortec spark tables out there. http://www.gearhead-efi.com/Fuel-Injection/showthread.php?1233-1998-Vortec-Timing-Table-%28Black-Box-Computer%29-Open-Closed-Throttle-ONLY! There are guys on this board that do tuning for a reasonable price. The engine is going to have to be in a vehicle and be driven under load before it can be tuned correctly. The LT4 hotcam is also lowering the vacuum signal to the map and the ECM thinks the engine is under load at idle. This is not the ideal situation for someone first learning to recalibrate an ECM. It may be in your best interest to hire someone to help. Most tuners will not attempt to tune an engine on a test stand with no load.

[rsicard]

Take off the jumpers from the resistors in the ECM. I would run the engine and get it to operating temp. I would start a datalog and try to fill in as many of the cells in the history table as I could for near idle. I would then run the data through the spreadsheet to lean it out. It may take more than one datalog to do this. You will only be able to partially tune near idle considering you have no load on the engine with it running on a test stand. With vortec heads, the spark table will have to be modified because BJYL was a calibration for a tbi headed engine. There are vortec spark tables out there. http://www.gearhead-efi.com/Fuel-Injection/showthread.php?1233-1998-Vortec-Timing-Table-%28Black-Box-Computer%29-Open-Closed-Throttle-ONLY! There are guys on this board that do tuning for a reasonable price. The engine is going to have to be in a vehicle and be driven under load before it can be tuned correctly. The LT4 hotcam is also lowering the vacuum signal to the map and the ECM thinks the engine is under load at idle. This is not the ideal situation for someone first learning to recalibrate an ECM. It may be in your best interest to hire someone to help. Most tuners will not attempt to tune an engine on a test stand with no load.

Need to fix IGNITION FIRST then tune VE tables. Any thoughts about ignition timing. TunerPro readout totally different from strobe on balancer.

[rsicard]

I need to beat this to death. The timing numbers in TunerPro have absolutely NO CORRELATION with the timing light on the balancer. No sense in swapping out the engine in the '95 pickup UNTIL the timing issue is first sorted out. Here comes the risk, if transplanting the 350 Vortec in its present state into the '95 pickup, and the timing issue is not sorted out, I am really dead in the water. Things may be easire to sort out on the run-in stand. VERY much understand only the idle ignition and VE table stuff can be adjusted on the run-in stand. Likely the timing issue MAY change for the better if installing the 350 Vortec in the pickup. Yet the risk in my mind remains. Your thoughts, please, on the ignition timing issue.

[rsicard]

Need guidance on TunerPro with 16197427 ECU on how to make Knock Sensor input deaf. Somehow there has to be a correlation between timing number in TunerPro and that read on the balancer with timing light. Took extra time to make certain number 1 cylinder was a Top Dead Center when installing graduated balancer and custom timing pointer. Previously with a carb and HEI distributor, the timing was just as it should be. With this EFI, the timing issue reared its ugly head. Suspect EMI/RFI interference. Howell harness, on run-in stand is limited in lengths. Not sure how much separation of wiring can be achieved. Don't know if its radiated or conducted interference. Don't know which wires and inputs are affected. Don't have de-pinning tool to disconnect select wires from ECU to isolate issue.

Would be nice to invoke thoughts from others on this forum. Your thoughts please.

[sturgillbd]

Balancer inertia ring slipped? Check TDC mark with a piston stop in the spark plug hole on #1 cylinder. If the mark on the balancer lines up with 0deg mark on the timing cover, and the piston is at TDC on #1, the inertia ring has not slipped. Unplug bypass wire and set the distributor to 0 degrees advance with the engine idling with the timing light. Shut off engine and pull battery power to the ecm. Plug bypass wire back up. Reconnect battery. Restart engine and look at timing with light and compare to tunerpro. What ignition module are you running in the distributor? With all of the knock counts in the datalog, your ecm is retarding the timing (just a few degrees). Do you have the proper knock sensor installed? Knock sensor should be for a 1993,1994 or 1995 5.7 truck with ecm controlled auto transmission. The manual transmission sensor is different. Do you have the wire from the knock sensor tied to ECM pin B15? If you want to disable the knock sensor, set the Minimum Temperature for Knock Retard (under Knock Retard Parameters in Parameter Category View) to max which is 151.3C and burn the bin a chip or upload it to the emulator. Triple check your wiring from the distributor to the ecm. How close are your plug wires to your test stand harness? I saw some glitches in your datalog while replaying it. Is your timing chain new? I use Advanced $0D TP5 v251.xdf and $0D-16197427-V5.7.adx . These two files can be found here: http://www.gearhead-efi.com/Fuel-Injection/showthread.php?303-16197427-PCM-Information-0D . There are just a lot of different things that can cause your issues. I am using a 16197427 in my jeep. I have not seen the timing issues you have with my setup. I traced each wire and labeled them as I built the harness. I have patched my bin to control the electric fan and by following the instructions and wiring diagrams on this and other sites, everything has worked. I suggest you go over everything. If the timing advance at the balancer is that far off from what the tunerpro data shows, something is wrong whether it be electrical or mechanical.

I sincerely hope this helps

Brian

[sturgillbd]

Homemade pin tool. It is a piece of solid copper wire like used in grounding a meter base for electrical. 6ga solid. I drilled a small hole in one end and inserted a header pin from a piece of scrap electronics. Soldered the pin in and viola! The tool was dipped in liquid tin to slow the tarnishing of the copper but it isn't needed

[rsicard]

Balancer inertia ring slipped? Check TDC mark with a piston stop in the spark plug hole on #1 cylinder. If the mark on the balancer lines up with 0deg mark on the timing cover, and the piston is at TDC on #1, the inertia ring has not slipped. Unplug bypass wire and set the distributor to 0 degrees advance with the engine idling with the timing light. Shut off engine and pull battery power to the ecm. Plug bypass wire back up. Reconnect battery. Restart engine and look at timing with light and compare to tunerpro. What ignition module are you running in the distributor? With all of the knock counts in the datalog, your ecm is retarding the timing (just a few degrees). Do you have the proper knock sensor installed? Knock sensor should be for a 1993,1994 or 1995 5.7 truck with ecm controlled auto transmission. The manual transmission sensor is different. Do you have the wire from the knock sensor tied to ECM pin B15? If you want to disable the knock sensor, set the Minimum Temperature for Knock Retard (under Knock Retard Parameters in Parameter Category View) to max which is 151.3C and burn the bin a chip or upload it to the emulator. Triple check your wiring from the distributor to the ecm. How close are your plug wires to your test stand harness? I saw some glitches in your datalog while replaying it. Is your timing chain new? I use Advanced $0D TP5 v251.xdf and $0D-16197427-V5.7.adx . These two files can be found here: http://www.gearhead-efi.com/Fuel-Injection/showthread.php?303-16197427-PCM-Information-0D . There are just a lot of different things that can cause your issues. I am using a 16197427 in my jeep. I have not seen the timing issues you have with my setup. I traced each wire and labeled them as I built the harness. I have patched my bin to control the electric fan and by following the instructions and wiring diagrams on this and other sites, everything has worked. I suggest you go over everything. If the timing advance at the balancer is that far off from what the tunerpro data shows, something is wrong whether it be electrical or mechanical.

I sincerely hope this helps

Brian

Brian: You are very good at this stuff. Already confirmed the balancer and timing pointer. I use it as the truth in timing. Just soldered 3.3 Kohm resistor in the Knock Sensor line to ground. Routed it away from the distributor. Connected a Fluke Digital VOM across the 3.3 Kohm resistor and read approx 2.1 vdc. Also check the AC volts on the wire and it was in the low milli-volts which is VERY GOOD. Can check the Knock Sensor wire that should be connected to B15. Will use teh xdf and adx that you are using. I am going to tear apart the harness and re-route the TPS, MAP and Knock Sensor wiring as far away from the spark plug wiring. Think this may solve the ignition timing issue. Also may set the Min Temp for Knock Retard to max setting to disable knock function. Right now it is dark outside and would be better to test tomorrow morning. Will relay the results to you.

Regards,
Rolly
Tucson, Arizona

[rsicard]

Homemade pin tool. It is a piece of solid copper wire like used in grounding a meter base for electrical. 6ga solid. I drilled a small hole in one end and inserted a header pin from a piece of scrap electronics. Soldered the pin in and viola! The tool was dipped in liquid tin to slow the tarnishing of the copper but it isn't needed

Is this the extraction or insertion tool for ECU connector pins/contacts?

[rsicard]

Balancer inertia ring slipped? Check TDC mark with a piston stop in the spark plug hole on #1 cylinder. If the mark on the balancer lines up with 0deg mark on the timing cover, and the piston is at TDC on #1, the inertia ring has not slipped. Unplug bypass wire and set the distributor to 0 degrees advance with the engine idling with the timing light. Shut off engine and pull battery power to the ecm. Plug bypass wire back up. Reconnect battery. Restart engine and look at timing with light and compare to tunerpro. What ignition module are you running in the distributor? With all of the knock counts in the datalog, your ecm is retarding the timing (just a few degrees). Do you have the proper knock sensor installed? Knock sensor should be for a 1993,1994 or 1995 5.7 truck with ecm controlled auto transmission. The manual transmission sensor is different. Do you have the wire from the knock sensor tied to ECM pin B15? If you want to disable the knock sensor, set the Minimum Temperature for Knock Retard (under Knock Retard Parameters in Parameter Category View) to max which is 151.3C and burn the bin a chip or upload it to the emulator. Triple check your wiring from the distributor to the ecm. How close are your plug wires to your test stand harness? I saw some glitches in your datalog while replaying it. Is your timing chain new? I use Advanced $0D TP5 v251.xdf and $0D-16197427-V5.7.adx . These two files can be found here: http://www.gearhead-efi.com/Fuel-Injection/showthread.php?303-16197427-PCM-Information-0D . There are just a lot of different things that can cause your issues. I am using a 16197427 in my jeep. I have not seen the timing issues you have with my setup. I traced each wire and labeled them as I built the harness. I have patched my bin to control the electric fan and by following the instructions and wiring diagrams on this and other sites, everything has worked. I suggest you go over everything. If the timing advance at the balancer is that far off from what the tunerpro data shows, something is wrong whether it be electrical or mechanical.

I sincerely hope this helps

Brian

Could not locate $0D-16197427-5.7.adx at that link. One of the downloaded files must have been renamed, yet don't know which one>

[delcowizzid]

dont worry about rewiring tps etc if it looks good in the logs.get it running and get the IAC controlling idle it could be retarding timing to try bring the idle down cause the iac cant.and fit an unmodded ecu and memcal that hasnt been converted for TPI

[rsicard]

dont worry about rewiring tps etc if it looks good in the logs.get it running and get the IAC controlling idle it could be retarding timing to try bring the idle down cause the iac cant.and fit an unmodded ecu and memcal that hasnt been converted for TPI

Thanks for the very good advise. Will remove the jumpers from the sense resistors. Then run the engine and watch to see if IAC sets a fault. Also will see if it will idle down as it should. If all that is successful, then can fine tune the on-idle to near 14.7 AFR on Wide Band.

[sturgillbd]

It is an extraction tool. Here is the adx file.

[rsicard]

It is an extraction tool. Here is the adx file.

You have been a great help. Thanks again.

[PJG1173]

didn't see this mentioned but when you converted to the 454 TB did you transpose the 2 IAC wires required for the 454 IAC? trying to find my old diagrams from when I switched to a 454 TB and had issues.

[Nasty-Z]

didn't see this mentioned but when you converted to the 454 TB did you transpose the 2 IAC wires required for the 454 IAC? trying to find my old diagrams from when I switched to a 454 TB and had issues.

Good catch .

Here is the wiring info:

BBC IAC –
Pin A - Lt blu/blk - Coil A Low
Pin B - Lt blu/wht - Coil A High
Pin C - Lt grn/wht - Coil B High
Pin D - Lt grn/blk - Coil B Low
SBC IAC-
Pin A – Lt blu/wht – Coil A High
Pin B – Lt blu/blk – Coil A Low
Pin C – Lt grn/wht – Coil B High
Pin D – Lt grn/blk – Coil B Low


TOM

[rsicard]

didn't see this mentioned but when you converted to the 454 TB did you transpose the 2 IAC wires required for the 454 IAC? trying to find my old diagrams from when I switched to a 454 TB and had issues.

First I have to thank you for the kind response. The folks on this forum are fantastic. Everybody, keep up the good work. The harness on the engine run-in stand, was fabricated by Howell for the 454 TBI system using a 16197427 ECU. No alterations have been made to the harness with exception of putting dummy resistor in place of knock sensor to settle some radiated interference to the knock sensor input. Yet, thanks for the heads up as to the differences between IAC wiring differences between 7.4L and 5.7L throttle bodies. The 5.7L uses a square 4 pin connector, whereas the 7.4L uses a oval shaped in-line connector. Am contemplating having additional in-line connector for IAC interchange connections between the two different throttle bodies. Need to do this on the '95 pickup, as the factory harness has the square 4 pin connector that needs to be changed to the oval connector to use the 7.4L higher air flow throttle body.

[rsicard]

Good catch .

Here is the wiring info:

BBC IAC –
Pin A - Lt blu/blk - Coil A Low
Pin B - Lt blu/wht - Coil A High
Pin C - Lt grn/wht - Coil B High
Pin D - Lt grn/blk - Coil B Low
SBC IAC-
Pin A – Lt blu/wht – Coil A High
Pin B – Lt blu/blk – Coil A Low
Pin C – Lt grn/wht – Coil B High
Pin D – Lt grn/blk – Coil B Low


TOM

Tom: Thanks ever so much for your post. As explained before, the Vortec engine on the run-in stand is using a harness fabbed by Howell for the 7.4L TBI system using 16197427 ECU and throttle body. Again, thanks for the info posted.

Regards,
Rolly
Tucson, Arizona

[sturgillbd]

With the engine idling faster than what is commanded, the ecm is going to bottom out the IAC. The ecm is also going to retard the timing trying to slow the RPM as delcowizzid stated. Have you found any more vacuum leaks? I just disabled knock, egr, and ccp in this bin. I also pulled 35% from the entire Idle VE table. Load this in your APU1 or burn to a chip after warming the engine up. Datalog and post the results. Most of your BLM's from the last log I looked at were at 90. This should help. I assume no responsibility from the use of this file. I recommend you look at the file and do a bin compare in TUnerPro to see what I changed.

Brian

[rsicard]

With the engine idling faster than what is commanded, the ecm is going to bottom out the IAC. The ecm is also going to retard the timing trying to slow the RPM as delcowizzid stated. Have you found any more vacuum leaks? I just disabled knock, egr, and ccp in this bin. I also pulled 35% from the entire Idle VE table. Load this in your APU1 or burn to a chip after warming the engine up. Datalog and post the results. Most of your BLM's from the last log I looked at were at 90. This should help. I assume no responsibility from the use of this file. I recommend you look at the file and do a bin compare in TUnerPro to see what I changed.

Brian

Cannot say enough good words for all your help. Will try the modified BJYL binary. Picked BJYL as there was a comment I picked up that this is the binary for export Vortec TBI. If this is not proper, just let me know. Just checked the four wires from the distributor to the ECU. They are good. Also replaced the module in the distributor. Will search for more vacuum leaks. For the first time will try to do a bin compare. Thanks again.

[sturgillbd]

BJYL is a calibration (binary) for a 1995 5.7 TBI engine, auto transmission (4L60E) with a 3.08 rear axle ratio. It isn't for Vortec and is not export. Most export bins are not closed loop because they don't use an oxygen sensor. They don't use the oxygen sensor because of Leaded gasoline. BJYL is a good calibration to start with.

[rsicard]

BJYL is a calibration (binary) for a 1995 5.7 TBI engine, auto transmission (4L60E) with a 3.08 rear axle ratio. It isn't for Vortec and is not export. Most export bins are not closed loop because they don't use an oxygen sensor. They don't use the oxygen sensor because of Leaded gasoline. BJYL is a good calibration to start with.

As far as vacuum leaks are concerned, the same 4 barrel manifold and holley carb generated 19-20 inches of vacuum at idle with the LT-4 Hot Cam. Will hook up the vacuum gauge again to the 454 throttle body and see what it says.

[jim_in_dorris]

Riscard, I haven't seen anyone ask this question, so I figured I ought to. Are you using your wideband O2 sensor in place of the narrow band sensor as an input to the 7427?

[rsicard]

Riscard, I haven't seen anyone ask this question, so I figured I ought to. Are you using your wideband O2 sensor in place of the narrow band sensor as an input to the 7427?

Have yet to hook up wideband O2 sensor. Need to get more serious problems under control first. One of the next phases of tuning will be hooking up the wideband O2 to the APU1 autoprom interface.

[rsicard]

With the engine idling faster than what is commanded, the ecm is going to bottom out the IAC. The ecm is also going to retard the timing trying to slow the RPM as delcowizzid stated. Have you found any more vacuum leaks? I just disabled knock, egr, and ccp in this bin. I also pulled 35% from the entire Idle VE table. Load this in your APU1 or burn to a chip after warming the engine up. Datalog and post the results. Most of your BLM's from the last log I looked at were at 90. This should help. I assume no responsibility from the use of this file. I recommend you look at the file and do a bin compare in TUnerPro to see what I changed.

Brian

Brian: Loaded the altered binary onto the flash chip. Ran the engine with it and it seems really behaved at first. Pushed the pintle back to full open position, started the engine, ran at higher RPM for short time, then settled down to good idle RPM. After it warms up at idle, goes from BPW of 1.x to 2.x. At the same time the wide band O2 says it is going to nearly lean cutoff, approx 16-17:1 AFR, then back less that 14:1. Does this in relatively slow cycles but continuous at idle and at the same time retards timing to after TDC according to timing light.

Suspect, maybe radiated interference from spark plug wire to TPS and MAP wiring which are on top of spark plug wires. Am going to splice in extensions of TPS and MAP wiring to reroute away from spark plug wires and the run BJYL-test-rsicard.bin again to see if the cyclic idle situation goes away. What does CCP stand for? Darn TLAs.

Made a recording of the run and attached to this post. Also attached image file of binary comparisons.

[sturgillbd]

CCP is charcoal canister purge. Part of the emissions control. I will open your datalog and have a look. Will post what I see in next post

[jim_in_dorris]

<QUOTE>Have yet to hook up wideband O2 sensor.</QUOTE> <QUOTE>At the same time the wide band O2 says it is going to nearly lean cutoff, approx 16-17:1 AFR, then back less that 14:1.</QUOTE>

Sorry, I am confused here. What exactly did you mean? Is the wideband hooked up or not? The reason I ask is that there is considerable debate about using a wideband in place of the narrowband O2 sensor as an input to the ECM. I looked at your data log, and your crosscounts are acting a bit strange. At times you get crosscounts, and at other times it stops. Also something to consider is the distance from the head to where the O2 sensor is attached. If the stock location is like my truck, it is about 4 inches from the head. If it is installed in the collector on a long tube header, the time difference between making a fueling adjustment and checking the O2 sensor to make sure it happened may be a problem. Just trying to throw out a few things that haven't been mentioned. Once you get your rich problem corrected, you will need to address your timing problem. Disable knock counts (being careful not to get too lean while tuning). There was a rather lengthy discussion on this forum about the difference between TP and actual timing that EagleMark did some work with, it might be worth your time to look that up.

[sturgillbd]

Well, the PCM never went into closed loop during that log. Did you disconnect the narrowband O2 sensor when you connected the wideband? Another thing that just came to mind.. Do you have any exhaust system past the oxygen sensor? If the sensor is getting air other than exhaust air on it, the readings will be all over the place. On this log, they werent and the O2 voltage just flickering around .440 makes me think you didn't have it connected.

Brian

[jim_in_dorris]

Brian, go back and look at his other log. You may be on to something, in that log, the O2 sensor mostly stayed above .660 and cross counts only happen occasionally. on most O2 sensors, the crossover is about .450 volts

[sturgillbd]

Jim,
The log test9.xdl had good O2 activity. Just mostly on the rich side and BLM bottomed out at 90. Crosscounts were active too.

[rsicard]

Well, the PCM never went into closed loop during that log. Did you disconnect the narrowband O2 sensor when you connected the wideband? Another thing that just came to mind.. Do you have any exhaust system past the oxygen sensor? If the sensor is getting air other than exhaust air on it, the readings will be all over the place. On this log, they werent and the O2 voltage just flickering around .440 makes me think you didn't have it connected.

Brian

Brian: I disconnected the NB O2 sensor and ran it that way. The wideband is still connected and working properly. There is an exhaust system downstream of the NB and WB O2 sensors. They are both near the junction of the exhaust manifold and approx 6 inches further down the header pipe. The two join each other on the RH side and then go through a muffler so as not to get the neighbors upset. Quite sure there is only exhaust passing by the O2 sensors as the exhaust is completely enclosed. Have read that VE tuning should be done in open loop mode.

Still getting cyclic BPW at idle along with Wideband AFR going high 16-17:1 then corrects itself just before dying and with larger BPW and retarded timing approx 10 degrees ATDC. The timing and BPW go together during this cyclic issue.

Also lengthened the TPS wiring and rerouted, relocated MAP Sensor such that its wiring is away from spark plug wires. Need to run it again and will connect the NB O2 sensor and keep the WB O2 sensor in the other pipe side. Just hoping the cyclic issue goes away. We'll see.

Comments appreciated.

[rsicard]

Brian, go back and look at his other log. You may be on to something, in that log, the O2 sensor mostly stayed above .660 and cross counts only happen occasionally. on most O2 sensors, the crossover is about .450 volts

First thing first. What are CROSS-COUNTS??? Please explain. Don't understand what this parameter is. Thanks.

[sturgillbd]

The VE table not being close will cause the surge. It was so rich on the other bin, I pulled quite a bit of fuel from it. It has to have the narrowband O2 sensor connected to make fueling corrections. It can be tuned open loop with just the Wideband data but wideband data isnt in your log. You might consider using the emulator portion of your APU1. Wouldn't have to keep pulling and burning chips. You can make adjustments and see the results immediately.

[sturgillbd]

Crosscounts are when the O2 sensor voltage goes above and below aprroximately .450 volts. At approximately .450 the fuel mixture is stoichometric or at 14.7:1 AFR for straight gasoline. If you open the data dash while the engine is running and you are datalogging, you can see the crosscounts as they happen. You can also see the BLM etc.

[rsicard]

The VE table not being close will cause the surge. It was so rich on the other bin, I pulled quite a bit of fuel from it. It has to have the narrowband O2 sensor connected to make fueling corrections. It can be tuned open loop with just the Wideband data but wideband data isnt in your log. You might consider using the emulator portion of your APU1. Wouldn't have to keep pulling and burning chips. You can make adjustments and see the results immediately.

Many thanks again. Pulling fuel from the VE tables has helped. At first startup, it was running very well. Next I will attempt to connect the Innovate LM-1 AFR DC voltage out into the APU1 autoprom. Then do another data recording to see the Wideband O2 data correlation with the remainder of the parameters. Then get setup to emulate. Can one emulate, record and data trace at the same time or is the data trace not necessary? Need to get a lot better with TunerPro ins and outs.

[sturgillbd]

Yes you can emulate ,view data and record at the same time.

[PJG1173]

Many thanks again. Pulling fuel from the VE tables has helped. At first startup, it was running very well. Next I will attempt to connect the Innovate LM-1 AFR DC voltage out into the APU1 autoprom. Then do another data recording to see the Wideband O2 data correlation with the remainder of the parameters. Then get setup to emulate. Can one emulate, record and data trace at the same time or is the data trace not necessary? Need to get a lot better with TunerPro ins and outs.

just a suggestion attach the 5v out of you WB to your linear EGR input on your 7427. I have found better results and easier initial setup this way than using the AD inputs on the apu1.

[rsicard]

just a suggestion attach the 5v out of you WB to your linear EGR input on your 7427. I have found better results and easier initial setup this way than using the AD inputs on the apu1.

Darn good suggestion. Thanks a bunch. Will do that.

[rsicard]

With the engine idling faster than what is commanded, the ecm is going to bottom out the IAC. The ecm is also going to retard the timing trying to slow the RPM as delcowizzid stated. Have you found any more vacuum leaks? I just disabled knock, egr, and ccp in this bin. I also pulled 35% from the entire Idle VE table. Load this in your APU1 or burn to a chip after warming the engine up. Datalog and post the results. Most of your BLM's from the last log I looked at were at 90. This should help. I assume no responsibility from the use of this file. I recommend you look at the file and do a bin compare in TUnerPro to see what I changed.

Brian

Brian: Just got done running the 350 Vortec and setting the idle screw hidden behind the plug. Also advanced the timing and readjusted the idle RPM. It is running VERY GOOD. Thanks again for all the help. Now I need to undo the knock, EGR and CCP one at a time. Is it possible to send image of each of these which were disabled in TunerPro? That will get me to the exact spot in the list and adjust them back one at a time to see what the effect is on running the 350 Vortec. Need to bone up on data tracing and adjusting the VE tables. The idle VE is a little on the lean side, but I think I will leave it there for now. Won't do much to the off-idle VE table till the engine is in the pickup and test driven to record the parameters and then adjust from that point. This will not occur until Knock, EGR and CCP have been returned to their previous state.

Rolly
KW7RS

[rsicard]

Brian: Just got done running the 350 Vortec and setting the idle screw hidden behind the plug. Also advanced the timing and readjusted the idle RPM. It is running VERY GOOD. Thanks again for all the help. Now I need to undo the knock, EGR and CCP one at a time. Is it possible to send image of each of these which were disabled in TunerPro? That will get me to the exact spot in the list and adjust them back one at a time to see what the effect is on running the 350 Vortec. Need to bone up on data tracing and adjusting the VE tables. The idle VE is a little on the lean side, but I think I will leave it there for now. Won't do much to the off-idle VE table till the engine is in the pickup and test driven to record the parameters and then adjust from that point. This will not occur until Knock, EGR and CCP have been returned to their previous state.

Rolly
KW7RS

Brian: I have found the Knock, EGR and CCP items that were altered. Don't bother sending any images as I will go to a previous bin and get the values. Thanks again.

[sturgillbd]

Did you ever datalog your running, driving vehicle? Did you ever test your timing light on that same vehicle? If I were you, I would narrow down a few possibilities. Test your timing light on the other vehicle with TunerPro connected to the ALDL stream. If it works as expected on your drivable vehicle, I would be suspicious of the aftermarket distributor. You could swap distributors and see if the problem follows the distributor.. Swap PCM's. See if the problem follows the PCM. Here is the first run of my 7427 TBI project. It was rich and overall ran like crap. This video shows the engine running with everything hot-wired and even used a jumper wire to start it. I had no switches, fuses or any kind of circuit protection. https://www.youtube.com/watch?v=IoyPCrM0nR8 During the first 20 minutes of running it after adding an adhoc cooling system to it, It killed a set of plugs. When I connected a laptop to it, with it running, the BLM was bottomed out at 90. It had a very pronounced surge at steady throttle and the rpm fluctuated between 500 and 1100 RPM at idle. After some minor idle VE adjustments, It starts, idles and runs great. When I set the base timing to 0 deg and reset the PCM, I glanced at the timing.with a light with it running. I don't have a dial back timing light but it was in the area where 20 advanced would be. That reminds me, I need to acquire a timing tape. I have not touched the open throttle VE table yet because there is no need until I can get the thing out and drive it at highway speeds to get data at varying loads and speeds. Check some of these points mentioned above and post what you find.

[rsicard]

Did you ever datalog your running, driving vehicle? Did you ever test your timing light on that same vehicle? If I were you, I would narrow down a few possibilities. Test your timing light on the other vehicle with TunerPro connected to the ALDL stream. If it works as expected on your drivable vehicle, I would be suspicious of the aftermarket distributor. You could swap distributors and see if the problem follows the distributor.. Swap PCM's. See if the problem follows the PCM. Here is the first run of my 7427 TBI project. It was rich and overall ran like crap. This video shows the engine running with everything hot-wired and even used a jumper wire to start it. I had no switches, fuses or any kind of circuit protection. https://www.youtube.com/watch?v=IoyPCrM0nR8 During the first 20 minutes of running it after adding an adhoc cooling system to it, It killed a set of plugs. When I connected a laptop to it, with it running, the BLM was bottomed out at 90. It had a very pronounced surge at steady throttle and the rpm fluctuated between 500 and 1100 RPM at idle. After some minor idle VE adjustments, It starts, idles and runs great. When I set the base timing to 0 deg and reset the PCM, I glanced at the timing.with a light with it running. I don't have a dial back timing light but it was in the area where 20 advanced would be. That reminds me, I need to acquire a timing tape. I have not touched the open throttle VE table yet because there is no need until I can get the thing out and drive it at highway speeds to get data at varying loads and speeds. Check some of these points mentioned above and post what you find.

Thanks again. Very nice for sharing experiences. Had the same experience prior to you leaning out my near idle VE table. Have not datalogged running vehicle. Purchased an identical PCM for test purposes. May be the aftermarket distributor. Don't want to swap distributors from running vehicle. Need to purchase timing tape for running vehicle and then hook up APU1/TunerPro and timing light. Also can try the recently purchased spare PCM first to see is the ignition timing situation changes for the better. May have had a bad other spare PCM. When push comes to shove, may have to build a bench stimulator to try many different PCM binary adjustments. Should have done that from the outset. Then could have removed running vehicle PCM, run and record baseline and then compare another test PCM and make it somewhat similar. Would be nice to bench test and find out all the other variables affecting ignition timing. Need to shield run-in stand EFI wiring. Likely ignition noise getting into TPS, MAP, CLT input wiring. May have to fab shielding for spark plug wires also to cancel cross-coupling noise.

Will try to get the engine run tomorrow with newly purchase PCM. Will let you know how it turns out.

[Loyd]

we had a the same problem with a 350 running 350 tbi on an adapter plate. there was a vacuum leak caused by the gasket set. replaced the plate, new gaskets and it ran much better. so make sure no vacuum leaks as the computer will sense low vacuum and put more gas. Good Luck

[ony]

see where your map sensor volt are, most of the stock engines I have seen are .90-1.14 with the tps volts around 55-65