Bad idle/running rich 3.2!

[michaelw]

Still trying to fix the rich condition on my 87 3.2. Replaced the 02 sensor and the DME. Car runs better, but idle, after taking rpm's up to 2500, falls down to 400-500, then slowly works its way back up to about 1000rpms and still have some black smoke. Idle also bounces a little on startup.

Tried to adjust the idle down (by shorting the circuit and turning the screw) but it won't budge no matter how much I turn the screw. What gives? Where should I check next? The idle stabilizer valve, the head temp sensor or airflow meter? Would the CO mixture affect idle and running performance?

Thanks guys, I am hunting the archives as we speak, but imagine somebody can save me some time.

Michael

[jtratza]

I know the feeling. There is lot's of information on this site for the condition.

I recently cured the problem (with the help of many here who responded to my similar condition, thank you very much) by replacing the temp head sensor, and then had the mass flow potentimeter resistance reset as per the supplier. Found out is way out of whack so it could have simply been it to start.

[nhromyak]

Is your ISV pulsing?

I would think it is either a problem with your barn door CO setting, or maybe a RPM sensor is bad.

Could also be leaky injectors...

Good Luck

[michaelw]

Originally posted by jtratza
and then had the mass flow potentimeter resistance reset as per the supplier. Found out is way out of whack so it could have simply been it to start.

How did you/they reset the the mass flow potentimeter?

Thanks,
Michael