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tazinhawaii
October 9th, 2006, 09:27 AM
I'm completely at my witts end now. Does the throttle cracker control any other parameters than just to add air when it's activated? The problem is this :

When the car is rolling my idle won't fall below 1600 RPM until it drops below the throttle cracker deactivate speed. This is with the clutch pressed or in neutral. BTW, this is on a 2001 Z06 Corvette with ETC. I can change the deactivate speed and the speed at which RPM's drop to normal change with it. I have tried making the TC airflow table to all zero's with the exact same results. I have also decreased the idle desired airflow table to as low as I can and still have the car idle with no real changes. I even went to some previous setups that this didn't happen with and it's still doing it... If it was a vacuum leak I would think it would affect idle as well and not only occur when TC is active.

I logged a bunch of time this was happening, and as soon as I go below the deactivate speed for the TC function, the throttle will shut and cycle to control RPM at idle. But above the TC activate speed, and my foot not on the accelerator (in neutral), the throttle won't shut below 7%. Also, my total IAC airflow will stay at 8.4 above or below the deactivate speed... I can set the activate speeds to 60 and 55 deactivaye and get the eact same results except at those speeds. Below 55 the car will come right down to idle, but obviously this defeats the purpose of the TC function...

Has someone else seen this?? Any ideas?? I'm letting the car cool now and then I'll check for vacuum leaks just because I'm out of other ideas...

Derrick

tazinhawaii
October 9th, 2006, 01:58 PM
After screwing with this some more, I have some interesting resultss now. I can get the RPM's down if I put the car in neutral (M6) and release the clutch pedal. The RPM's stay up until I release the clutch though. But when I press the clutch back in and put it back in gear (all while rolling above the TC activate speed), the RPM's stay down near idle. With the A/C on, it's just worse (it hangs about 300RPM's higher). The long term IAC correction is .5 while the short terms are all 0.0. I also verified that the PCM is seeing the cclutch depressed when it is.

Thanks,
Derrick