Car Sputtering Part two.

[IDRIVEAG8GT]

So, now with the 808 version of the beta, I am still having this stupid issue where after a WOT sprint the transient fuel begins to have a delayed effect.

I have attached a log (albeit long, but you can see what I'm getting at) But the quick rundown is, on the first start after a write the car runs and operates perfectly during rapid throttle transitions and the injector pulse is nice and smooth during the "pump shot" of rapidly opening the throttle. It works no matter what I do. After killing the car and restarting the engine, the transient fuel effect still works fine UNTIL going WOT, then it all goes to hell!

The typical response time of the injector working properly is 2-3 hundredths of a second. After it screws up, the injector response time is ~1 tenth of a second

This makes the car stumble when taking off from a dead stop, or changing throttle position to accelerate in traffic and it sucks!

Again, the log and tune are attached. Please if you have any questions, comments, or concerns let me know. And also, please try not to make fun of the INJDC% at WOT. My LS9's are getting swapped tomorrow for ID850's and a different supercharger pulley.

I'm driving myself insane trying to figure this out. And I have literally torn my car apart trying to find a mechanical issue. NADA!

Thank you,
-Robbie

[FASSTRUK]

On my n/a tbss I had the same issue, also my O2 millivolts went up to 940 once wot finally "kicked in"... After a few days of normal driving to and from work everything seemed to work fine and the wot O2 Mv's seemed to level off to a max of 907. Strange, it's like the PCM learned wot and adjusted to meet a consistent afr.

[IDRIVEAG8GT]

On my n/a tbss I had the same issue, also my O2 millivolts went up to 940 once wot finally "kicked in"... After a few days of normal driving to and from work everything seemed to work fine and the wot O2 Mv's seemed to level off to a max of 907. Strange, it's like the PCM learned wot and adjusted to meet a consistent afr.

Mine never "learned"

[carlrx7]

you running maf or ve?

[IDRIVEAG8GT]

you running maf or ve?

2.5 bar SD. What's baffling me is that it does it regardless of what mode it's running in.

I also noticed that whenever transient fuel is working right and I "burp" the throttle, the injector pulse is nice and linear, and then after it messes up and I "burp" the throttle, the injector pulse becomes jagged, as does the change in spark advance.

[turbo 6l]

take a good hard look at torque managment/general/fast torque exit /fuel and spark still enabled .. i do not know what these do but sounds awful close to what your describing .. according to the note at the bottom of the screen when cursor is on them .and im still learning and playing with this ecm ..just to throw this out there hth

[IDRIVEAG8GT]

Still working on it. Heading to the shop right now to swap injectors.

[IDRIVEAG8GT]

Injectors changed and upped the boost to 11.5psi. ~75% INJDC.

Still same issue.

[IDRIVEAG8GT]

I can't be the only person having this issue?

[carlrx7]

ok, do you not have a maf? why is the table all zeros?

i swear these ecu's still look at the tables even in maf/sd only modes. example.

I like to run maf only. but was having lean tranisitions, my ve was about 25% too low, i never adjusted it after a scale. i did a quick tune of it and got it within -3 stfts and switched it back to maf only, now its perfect.

also, in the dtc's i thought you leave the ses enable and use mil on first, or uncheck ses and use no error report.

maybe try a rewrite entire as well?

-Carl

[IDRIVEAG8GT]

ok, do you not have a maf? why is the table all zeros?

i swear these ecu's still look at the tables even in maf/sd only modes. example.

I like to run maf only. but was having lean tranisitions, my ve was about 25% too low, i never adjusted it after a scale. i did a quick tune of it and got it within -3 stfts and switched it back to maf only, now its perfect.

also, in the dtc's i thought you leave the ses enable and use mil on first, or uncheck ses and use no error report.

maybe try a rewrite entire as well?

-Carl

Thanks Carl. There's no MAF at all. Pure SD. I tried reinstalling the MAF and it did the same damn thing.

As far as I know I got it in SD correctly. It sets the codes but doesn't MIL so I think I'm good.

Just tried a Write Entire. No dice.

This issue is only pertinent to E38's so far as I know :/

[carlrx7]

Thanks Carl. There's no MAF at all. Pure SD. I tried reinstalling the MAF and it did the same damn thing.

As far as I know I got it in SD correctly. It sets the codes but doesn't MIL so I think I'm good.

Just tried a Write Entire. No dice.

This issue is only pertinent to E38's so far as I know :/

mines an e38, no issue. 2.5 sd os too.

-Carl

[IDRIVEAG8GT]

mines an e38, no issue. 2.5 sd os too.

-Carl

So weird. I wonder if my ECM just decided to crap.

[BigDaddyCool]

interesting......... so your o2's are sticking and responding slow causing lean conditions right = the stumble on/off throttle..... seems very similar to the issue i have which i beleive is caused by the idle air bypass valve, even a map sensor i don't think will pick that up.

The odd issue after restart, injector heatsoak causing delayed response? watch car voltage as well.

those trims are way bad

[IDRIVEAG8GT]

interesting......... so your o2's are sticking and responding slow causing lean conditions right = the stumble on/off throttle..... seems very similar to the issue i have which i beleive is caused by the idle air bypass valve, even a map sensor i don't think will pick that up.

The odd issue after restart, injector heatsoak causing delayed response? watch car voltage as well.

those trims are way bad

It's only after a WOT pull, doesn't matter if I'm on it for a half second or whole minute.

The trims change too after that run. Look at the log, you can see it takes the injector much longer to increase Pulsewidth than before. Also, as the scanner plots data such as timing and Pulsewidth during throttle transitions, it goes from a nice smooth line, to one that's jagged.

Go figure.

[IDRIVEAG8GT]

A few betas ago I didn't have this issue, then it started heavy lean spotting during transients so I had to start adding more fuel in that area. Ever since then it's been acting strangely.

[ingsteve]

IAT correction factor and other coefficients?

[IDRIVEAG8GT]

IAT correction factor and other coefficients?

Don't think so. :/

[carlrx7]

flash it with an older beta, i got a shit ton saved.

[IDRIVEAG8GT]

flash it with an older beta, i got a shit ton saved.

I need a beta from like three to four betas ago.

You have one?