E38 Speed Density Idle Rich AFR No Matter What I Try

[Jgarretts86]

2008 C6 Vette with E38....
I have the MAF tuned pretty good and now I am working on the speed density tuning. MAF disabled, Dynamic High RPM disable set to 8,000 rpm, Fuel Trims turned off, P0103 set to MIL on 1st Error. I can crank the car and let it warm up and begin logging commanding 14.1 AFR. Car is running very rich at 12.0-12.5 AFR. I log the AFR error and copy paste to the VVE table. Interpolate as much as possible within the VVE zone, Calculate Coefficients, Flash the tune to the car, and no change in idle AFR. Still 12.0-12.5 range. What am I doing wrong? Is there a fueling multiplier table somewhere I am missing? The car is for sure in Open Loop and the MAF is showing as failed. What am I missing? I even took 15% from the entire VVE table with no change in AFR. SD Tune attached. Thanks

[doorev800]

read up on "Rich after flash" your injector tip temp sometimes starts at 100*c after you flash so it richens up the mixture until it lowers back down to normal operating range of 50*c. Normally I log the injector tip temp and intake valve temps and start doing actual logging when both those are in their operating ranges:

Injector tip temp:40-50c
Intake Valve temp: 140-160c

[Jgarretts86]

Fuel-Open Loop/Base-Open Loop Gains..... I have all of these tables set to 1.00 so they don't mess with my commanded AFR. The multiplier range is form 0-2..... Should I have 0 in all the tables? I figured setting them to 1.0 would keep the commanded as set. This is how I had the tables set for my MAF tuning and I had no issues.

[doorev800]

look under engine-fuel-general-offset-offset vs injector temp. now if you look at that chart and your injector tip temp is say 100c after flash, this is a adder to the injector pulse width that will richen the mix.

log what i said and see how your afr is after ITT and IVT are back to normal


edit- i see you have your open loop and open loop gains all set to 1.0 so IVT wont be a issue, but I bet your injector tip temp is what is richening it up.

good luck!

[Jgarretts86]

Thanks guys, I?ll give that a try when I get off of this hurricane storm work!

[Jgarretts86]

Well, I tried everything mentioned above..... car still runs pig rich at idle. Getting some bad camshaft reverberation as well, even on the clean MAF tune. About 1500-2000k cruising in 5th, I can feel the car jerking.

[doorev800]

Post a log

[dirtydime]

I took a quick look at your tune. Only thing I saw is your pwr enrichment delay is set at 200rpm and 48% tps. May wanna bump the delay up to 4k rpm in case you go over 48% throttle position while logging data. What the other guys said about injector temp does make sense cause mine is always rich for a minute after flashing new tune.

[Jgarretts86]

I still cannot get this thing to respond to any changes I make in SD. I have put all zeroes in the injector temp table and bring car up to operating temp, so that rules out Rich after reflash I would think. The MAF is showing to be Failed and its throwing the SES for P0103. Car is for sure in open loop. It idles at 11.7-12.2 AFR no matter what changes I make to the VVE table. I have even isolated it to just the specific ZONE that the motor is idling in and took away 20 percent in the entire zone with no change in afr at all. What gives???? I can load the OL MAF only tune back in it and life is good.

[Sub8]

Did you change all of the vve tables to be the same?

[Jgarretts86]

I did. Even the DOD ones just to make sure that wasn?t the issue. I will post a log file tonight.

[Jgarretts86]

I also put all 0 in the maf frequency table to rule that out as well.

[eXo3901]

Post a log showing the problems you are having and post the tune to go along with that particular log.

[Jgarretts86]

SD Tune and Log file attached... This is with 20 percent pulled from the VVE from 1600rpm down. Still 10 percent rich of commanded.

[Jgarretts86]

Also, on my MAF tune, in open loop it runs and idles at commanded afr. Soon as it goes into closed loop, the LTFT maxes out at like 24.2 percent and it goes really rich into the low 12s. Reset the LTFTs and it cleans up for just a second then right back to super rich.

[FASSTRUK]

It looks like you are in pe all the time, 15 kpa, throttle is set at 3, and eq ratio is 1.177. raise the kpa enable to 90, and see if that stops your rich readings

[Jgarretts86]

Yeah I?m putting it into PE right off idle to fight some cam reversion in the low rpm ranges while cruising in 5th and 6th. This is temporary until I get a tune built to isolate the trouble spots with reversion. But it?s not in PE at idle and is commanding 14.6. Or at least that?s what the scanner shows. I will raise the PE and try it just to rule that out.

[Jgarretts86]

Raised the PE enable you 90kpa. Still idles way rich of commanded in OLSD. And on the maf tune it idles at commander 14.6 but when it goes into closed loop the fuel trims still go 24 percent rich. Possible bad o2s? But that still doesn?t explain the rich idle in OLSD.

[cadillactech]

What are you modifications?

[Jgarretts86]

237/246 113+3 625/605 Lift
Forged pistons 11:5 static compression
Long tube headers 3? exhaust no cats.