kornfan_88

Alright, when my car gets up to normal operating temp it starts ti idle up and down from 900 rpm to about 400 and then back up. I have a new IAC, TPS, 65mm TB and spacer, MAc cold air and MAP sensor. What could the problem be?

makarovboy

Check for obvious vacuum leaks and codes (assumming that this is a 5.0 mustang) At the back of the engine, between the intake and firewall are two large plugs, one black, one white. Inside each are 10 male and female connectors. Don't pry the clips to open the plugs, you have to sqeeze them together.

Take a nail or a sharp punch and gently spread the male contacts. This will assure a tighter fit. If you get one or two too wide, gently pry them back with needle nose pliers. Use a generous amount of spray contact electrical cleaner to clean up the contacts. If all else was good, this should clear up the problem. Hope it helps.

kornfan_88

Ok, I'll try that. Also I noticed today that it is blowing some black smoke out of the exhaust. Would this have anything to do with it?

converted

Do you have any significant mods like a cam, heads or intake? Problem sounds familiar, but I want to know this info before throwing out the advice.

kornfan_88

The engine is all stock except for the throttle body and cold air intake.