Low RPM Lean Issue on 96531706
I've been having some drivetrain issues...The car is currently incapacitated.
That last update was after a pretty brief test drive while checking some drivetrain stuff out.
ECU wise, I've been going through the CAS driven stuff that determines spark and fuel timing. I'm not sure if JCSBanks and MRfred went through all of it already or just through the IPW section.
Having looked at some of the sub-routines though with this problem in mind, I could see how being slightly off on the VE tables under certain conditions could REALLY cause problems. Under certain load levels, you can trigger sub-routine branches that I think we have assumed up to this point would never be used.
That last update was after a pretty brief test drive while checking some drivetrain stuff out.
ECU wise, I've been going through the CAS driven stuff that determines spark and fuel timing. I'm not sure if JCSBanks and MRfred went through all of it already or just through the IPW section.
Having looked at some of the sub-routines though with this problem in mind, I could see how being slightly off on the VE tables under certain conditions could REALLY cause problems. Under certain load levels, you can trigger sub-routine branches that I think we have assumed up to this point would never be used.
Last edited by 03whitegsr; Jul 31, 2010 at 11:03 PM.
My condition occurs at less than 15% throttle and below 3000 rpm. I never noticed any "issue" until I installed FIC blue max 1450cc injectors. I have the fuel trims pretty good so I am not certain that they are the direct cause. Crazy thing is that if I exceed the 15% throttle position the condition is gone. No hesitatsion, no stutter, nothing but a clean, easy, stock like run.
I am trying to adjust the Asynch tables in this rpm range but I really do not fully understand which table does what.
I am trying to adjust the Asynch tables in this rpm range but I really do not fully understand which table does what.
Evolving Member
Joined: Jul 2009
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From: MA
From a John Bradley suggestion I changed my MAP/VE table to have slightly higher load values than MAP/KPa values coming on boost at the 80 and 100 KPa cells. This completely cured this issue and I was able to dial back the resulting rich condition to match map AFR pretty easily. I noticed at least 03white still had lower load values than KPa, thus correcting lean in the last screen shots of his VE that I have seen. It doesn't take much just a couple points past 1:1 did it for me
(AFTER)This is my current set-up, no lean tip-in:
(BEFORE)This one has lean tip in:
(AFTER)This is my current set-up, no lean tip-in:
(BEFORE)This one has lean tip in:
Last edited by 95630706; Aug 2, 2010 at 08:23 AM.
I've been playing with timing settings in the below 70 load and below 3500 rpm. I found that lower timing values make the car much happier.
Start with the stock values. Smooth the curves. Car is happy. Stutter is very, very minimal if not....gone.
Start with the stock values. Smooth the curves. Car is happy. Stutter is very, very minimal if not....gone.
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