Need Help! IACs low, RPMs high, and powerlogger file says Park/Neutral on ECM I/O


Dec 29, 2004
Can someone take a look at this power logger file? My car seems to be running really well since I have been finding and fixing problems. I can mash the accelerator now and get lots of wheel spinning and a smooth acceleration with no stumbling! This is the first time in the last few years I have been able to get it to this point.

I haven't learned to read into the powerlogger files yet, but I notice a few obvious things-
*My AF is running around 11 in park, car running,
*My IAC is 0 in park, car running,
*My RPMs are high at 1600 in park, car running.

I also noticed that the powerlogger file on the data page shows the ECM I/O checked as park/neutral when the car is in the middle of accelerating :confused:-that just doesn't look right...

Please take a look and let me know if there is anything obvious about my car's readings and running characteristics. Thanks.


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Adjust the IAC. That should bring down RPM and MAF#.

The park neutral switch is in the column. Assuming a floor shift car, does your column turn when you move the shifter? Linkage still hooked up?
I have the IAC adjusted with 1.5 threads showing and the TPS at .42. What should I do to adjust the IAC? It's showing zero with these settings.
Your IAC # on the scanmaster should be around 20-30 engine warm @ idle.

You need to close the throttle plate some.(turn screw out)

Considering the TPS is connected to the throttle plate, you will need to readjust that as well.

You will go back and fourth between TPS and IAC before you get it perfect.

I cleaned out the throttle body and plenum, then replaced seals and gaskets. Solved the problem. IAC at a steady 10 at idle, TPS at .40, and AF at 6. Best I've seen in years.