question about cars being temporarily rich after flash programming

[hexdmy]

I've done a bit of GM tuning, primarily on the older LS1B controllers, however I did tune a 2010 Camaro with an Edelbrock supercharger some time ago and struggled a bit with the fuel trims. It seems that I could tune it on the dyno, then go drive the car and the fueling would shift lean considerably at light load, and I would have to go though the MAF table again, using data I collected during the drive. This was a few years ago, and it was using another piece of GM tuning software. I now have EFILive, and an opportunity is coming up where I may need to tune a E67 controller on an engine swap, so I have started reviewing the tuning process again for these controllers. Interestingly, and on another forum, there have been a few threads on this "rich after flash issue", one person actually documented it on the bench using a simulator, and it appears that the ecu applies a small pulse width offset after a reflash on a hot restart of about .3ms that slowly goes away if the engine is run for about ten minutes. Another observation made by several people on that forum, is that you do a couple of hard pulls on the dyno, the offset seems to go away faster.

Looking around the EFILive forums, I don't see any mention of this issue, which is surprising because it says to me that either people using EFILive are not having the issue, or are just not observing the issue. I would say that on a stock engine, the offset is annoying by not too much of an issue, however it becomes a big issue once you install large injectors or if you are working with a heavily cammed engine which tend to be sensitive about the air fuel mixture.

So I have brought up this topic to ask these questions:

1 - are others experiencing this rich after flash issue with the E38 / E40 / E67 controllers ?

2 - if so, does anyone know what causes this issue, and can EFILive chime in on this ?

3 - again, if this is an issue using EFILive as well as other tuning suites, would it not make sense for the software company(s) to look through the GM code to find out what is going on ?

Any thoughts or suggestions are appreciated.

[bballer182]

I've read of others with this issue. Even with HPtuners. I think its an ECM thing. Probably just defaulting to a rich mixture as set by the factory for a safe first start and run if I had to guess.

[LSxPwrdZ]

I too have observed this issue. So far the only work around I've come up with is to wait 10mins after a reflash to begin logging for fueling errors.

[GMPX]

A lot of learned data in the ECM's RAM gets cleared and reinitialised with default values after a reflash, that is just how the ECM's operate when they detect they've been reflashed.

[auspeed]

https://www.hpacademy.com/blog/rich-...oblem-and-fix/

[Philbar715]

I may have missed it, does EFI Live have access to this table? I looked and I see this table on my E40 in HPT but not in EFI Live.

[auspeed]

I may have missed it, does EFI Live have access to this table? I looked and I see this table on my E40 in HPT but not in EFI Live.

I would also like to know the answer to this question?

[finishline]

Did this ever get resolved? Going on 4 years now.

I never understood how to do the cax files. Quite frankly EFI Live should have included everyone's cax files into the O/S so that we all could
do a better job of tuning our customers cars. So sad, leaves us no choice but to MOVE ON to another tuning platform. This lack of support is
the reason I didn't purchase the E67 Stream and only use the "other software" for tuning the DI Engines.

At one time this was the best software and there were a ton of great people here but they have moved on as well.

Joecar, your the best and your help was always appreciated.

I'll check in occasionally but this place is turning into a ghost town due to lack of product support.

[Tre-Cool]

ive never experianced the issue on any e38/e67 i've tuned with efilive.

probably more of an issue restricted to hpt with their custom ve OS.

[pinstripebob]

Is this related to table B0147? I'll need to log injector tip temperature, but B0147 is a multiplier to open loop commanded AFR based on injector tip temperature, similar to the discussion in that HP Academy link posted above.

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