Stoichiometric
March 25th, 2007, 02:31 PM
I have been tuning my 2002 ZO6 (440CI Fast 90/LS2TB, 232/240 117 cam) for a while and have everything dialed except for the idle. It idled smoothly at 850rpm , but would hang throttle 15% opening 1500 rpm, in gear and out of gear until I come to a stop (0 mph) for about four or five seconds then it drops to 7% opening and 850 rpm. I tried a number of suggestions from this forum an I found two things that were different for me. I first tried lowering the ETC throttle Area conversion B4349 from the stock .025 to .015 as was suggested and the idle surged severely from 300 rpm to 1400 rpm occasionally dying. I then kept raising this above my factory setting of .025 and it got better so I am now at .05 (B4349), no more surge. Now I have the hanging throttle, so I lowered my ETC Max Position for Idle B2713 from stock 18.3 to 9 and the hanging rpm was greatly reduced to about 1100 rpm, I then thought I was on the right track so I lowered it to 7, and everything was perfect. I then came to a stop sign turned off the motor and tried to restart it which sometimes would bring back the problem and it would not restart. I could hear that the fuel pump would not turn on and I had error messages such as coolant temp 270, reduced power, ect. I tried to reflash a previous tune and I could not establish communication with the PCM, I did a test and it said communication error no recovery options during the attemps at reflash. I am currently downloading the latest V1 software and will try a reflash with that. Is my PCM dead (needing replacement) or can I recover it? Any comments on what I did and need to do are appreciated.