LSJ idle higher tps than normal after driving, tiny pedal tap fixes idle?

[eronq9]

So my 2004 Saturn Ion Redline likes to hold higher than normal tps values when coming to a stop and run real low timing to try and keep rpms down, however if all I do is give it a tiny tap on the gas it will drop ~2% TPS and then idle timing will bump up to reasonable values. It seems to do it more often with the AC on. I managed to get a log with it happening and me doing the little taps. The car also likes to hold a pretty high tps on coastdown with AC on causing coastdown rpm to sit closer to 1400-1500rpm at times.

At this point I don't really know what the PCM is trying to do so I may attempt having the dealer do a clean wipe and reinstall of the latest OS and then reflashing my tune.

Here is a Pic (Green Reference Line is 0deg timing Advance)
Capture22.PNG

Mods:
E47 blend Fuel
60lbs Injectors
2.7 Pulley
K&N CAI
3in Full Exhaust
Dual Pass Endplate
Option B

[Boosted C6]

got a copy of the tune?

[eronq9]

got a copy of the tune?

Attachment 61174

[Boosted C6]

how are your fuel trims? And I see your running VE which is very wavy. try to keep it smooth and that may help.

[eronq9]

how are your fuel trims? And I see your running VE which is very wavy. try to keep it smooth and that may help.

When using MAF only the idle actually does this more. Fuel trims seem to go rich as IATs go up when sitting idle as well, might be the K&N getting hot.

Its just sucks that it idles perfectly if I just give the throttle a tiny tap.

[cobaltssoverbooster]

you have 2 sets of different ignition maps. try setting the base maps to match each other to fix ignition. i would also fuss with the idle ignition to improve idle quality. i never had a file that left it stock.

im guessing your running an ethanol blend lower than e85...perhaps e60?
not to hurt your feelings but your ve table looks like doo doo. I would highly suggest running a boost referenced return regulator in this vehicle for multiple reasons. 1) i prevents the last cylinder in the rail from running lean 2) Its easier to tune idle because of reason 3) the injector data is much simpler and it is also a heck of a lot easier to adjust to ensure the ve table stays smooth.

if you are currently tuning VE, you are doing it wrong. the maf sensor is still enabled. you must set the maf fail high value to 0 hz and set the P0101 code to "first error", uncheck ses box so the light doesnt annoy you. set dynamic airflow to max rpm so maf is not used.
you have to shut defco off or else it will cause issues with the ve table values.

start with locking in the injector data and fuel offsets. then work into the idle ignition characteristics and main ignition table map blending.

[eronq9]

I already tuned the VE, I do fail the MAF when I do so. The tune file I posted is with everything turned back on.

Not sure why it results in the way it does but I'm guessing it has something to do with the 60lbers. I'll go ahead and tune the VE some more and see if it helps.

I have been thinking about doing a different fuel system to help with it as well.

I'm still not sure why the PCM holds a high TPS when coming to a stop and gets stuck removing all the timing to hold idle instead of closing the throttle plate more. If I give it that tiny throttle tap at a stop light, it always results in a stable idle.

[eronq9]

Alright so I went through and smoothed the whole VE table, retuned VE again several times, resmoothed it again and all my cells, besides the decel, are within about 1.5% after logging.
I bumped up base spark to 15, bumped up coastdown to match, and then copied high octane to low octane.

New VE.PNG

Im going to retune my MAF just incase its off and see how it responds afterwards.

[cobaltssoverbooster]

thats what a ve table should look like...great job mate

i believe you will find the idle ignition and coast modifiers will correct your hanging issues now that fuel is on point.

[eronq9]

Car still seems to hang once it gets warmed up. When I push the clutch in it will like rev 1500rpm and will sit there with 12.5% Throttle. Interesting enough, if I go into open loop with the MAF failed and VE only the coastdown rpm will stay around 1200rpm and TPS is in the 11% area.

Its like the PCM is refusing to learn idle Throttle Position, but only with the MAF enabled, also not sure why my cars idle goes to 872 "desired rpm" when the AC is on, when my friends 2007 cobalt will stay at 850.

I will post up a log of this to see if anyone has any ideas