Off idle stumble(FAST)

[turbobitt]

I am still batteling my off idle stumble with little improvment. I have maxed out both map and tps rate of change tables with no effect. AE vs. TPS position is set to 100% for most of the TPS range. I can cause a over-rich condition if I stab the throttle but my problem happens when the throttle changes very little which always results in no ADDITIONAL AE FUEL.
For example , If I slowly ease into the throttle , lets say 2-3% change, I get no AE fuel or map AE fuel and DELTA MAP and DELTA TPS remain 0 even though I can see a change in both TPS % and map. How can I change the sensitivity of the system to react and fix the problem??

Also , No vaccum leaks, Full tank of fuel, good fuel pressure, car runs well eveywhere else.

Allan Gorneault

 

[Craig Smith]

Delta MAP and Delta TPS fuel are applied by the ECU in a manner that often doesn't allow you to directly see that it is being applied. Those two sensors probably won't ever change state, to be honest. The additional fuel they apply happens very quickly; that process generally starts and ends well within the time allowed for a screen update.

If you data log the injector pulsewidth you will likely see the changes there. I'm willing to bet that your stumble is being caused by too much AE fuel at this point, given that you have maxed everything out.

 

[turbobitt]

My stumble is definetly lean , My data log(s) show a/f pegging out over 15 to 1 .
Remember - I can make it stumble from an over rich condition ONLY if I stab the throttle with the graphs maxed out BUT still no AE fuel with tip-in.
PLEASE HELP



Allan Gorneault

 

[RickWI]

Guess what I would do is data log the stumble (s) and increase the VE's in those cells.

 

[bobc455]

Rick makes a good point- is the rest of the VE table already accurate? AE would only be a band-aid if the rest of the table isn't accurate. You shouldn't be reading 15.0 (unless that's where your A/F table is set, in which case that's another possibility)...

Also, is your timing table set up reasonably well?

If all that is set up correctly, then I wonder if there is too much AE MAP correction.

I see you're in CT, maybe we can meet up and play a bit some weekend- I'm in Mass.

-Bob Cunningham
bobc@gnttype.org