Been trying to get my idle right for over a year with no luck. I need help

[Deputy_Dangle]

Alright guys,
I have been trying to get my car to return to idle properly for over a year with no luck. The car almost always stalls on clutch in or when coming to a stop in neutral. I am to the point of selling the car if I can't get this fixed so I come here for help. The car is a 97 Corvette, i recently swapped over to a 0411 PCM hoping that would help solve my issues with not much luck. The cars set up is as follows:

97 Corvette with 01 0411 pcm\ Manual trans
Ls1 347
TFS 225 heads
Fast 102/102
LT's
FIC 42# injectors
Aeromotive FPR set at 43.5 psi (return style system),
TSP Trq2 cam 232\234 112lsa
Monster stage 3 clutch and 18# flywheel

The car is SD and runs the 1 bar SD OS. The car has 2 Innovate widebands both being used to simulate NB's and also log WB on the scanner through EGR.

I have ran the RussK idle config and the RAF numbers seem to be good. The STIT seem to hover in the -.3 to -.5 range. The timing seems to be good and the idle is very steady if it actually catches idle. Ive went so far as to jack the RAF number up very high which seemed to help a little but I still got a stall fairly often, not to mention a lot of surge. I also played with the rolling idle table, which helped somewhat but did not solve the issue.

The numbers in the VE are unusually high. I used the injector data supplied to me by FIC when I purchased their injectors. I'm not sure if the data id bad or if the high numbers is the side effect of the vacuum reference regulator.

I have checked, double checked, and triple checked everything mechanical and have found nothing wrong. No vacuum leaks or fueling issues. I've attached a short scan I made tonight where the car goes to stall several times and I save it by blipping the throttle. The scan was done in OL, I believe I have an exhaust leak on bank 2 so I haven't put the car back into CL yet. In the scan Frames, 442, 694, & 732 all exhibit the stalling.

The attached tune also has 2.7 g\sec added to the rolling idle table in an effort to keep the car from stalling. Which didn't help much. Also, about a month ago I installed a friends new wideband in place of mine to insure I wasn't getting incorrect data which checked out ok.

Any help is appreciated!

RunScan0411 6.hpl
Working tune Z06 Timing table Rolling idle Rep Timing.hpt
Corvette Config file.cfg

[sevinn]

I'm on mobile so I can't look at your files but see if any of this is useful:
http://www.hptuners.com/forum/showth...-idle-problems

[Deputy_Dangle]

I actually just read through that a few days ago. I played with the TF airflow/decay/delay a good bit over the weekend without any luck. At one point i jacked the RAF up by 5 g/sec just to see what would happen. Most of the time the rpm's would hang around 1500 until i reached 0 mph, then either drop to the 1000rpm commanded idle or surge a few times and die. But even with the RAF over inflated there were sevretral occasion where the rpms would dive to 0 on clutch in. It hasme baffled.

Back when I was still running the 97 PCM, it didn't completley solve the problem but it helped some if I severly leaned out the idle cells and the decel cells leading to idle. But I mean very lean, my WB would read around 19-20:1 but the idle was still very stable which lead me to beileve The wideband may be innacurate at idle. I did check the accuracy of the wideband with a new one just to be sure the sensor wasnt bad. I dont mind the cars idle being that lean if that is what it need to work, but you could tell the car was lean when you attempted to pull away from a stop, it was very laggy and lacked response.

[Deputy_Dangle]

I returned the TF and rolling idle tables to stock and made a few scans , the first is a drive down the street where the car stalls several times on clutch in. The other two scans are idling in the drive way with quick blips of the throttle to around 2000rpm which also both result in stalls. Same config as above.


RunScan0411 7.hpl
idle blip 1.hpl
idle blip 2.hpl