Originally Posted by kelly201
I recently bought a 1995 Ford Taurus 3.0 L with 65000 miles. The car looks and runs fantastic when you first start it. After about 30-45 minutes when I come to a stop the car starts vibrating a little and the idle speed decreases. The oil light also starts flickering when this happens. I can put it in neutral or sometimes just turn off the A/C and the idle speed increases and there is no flickering. I know this car had overheated prior to my purchase and the head gasket was replaced.
I can turn the car off for a few minutes and when I start driving it again the whole process repeats.
I considered just trying to set the idle speed up just a little to see if that would solve the problem if I can figure out where the adjustment screw is.
The idle speed is controlled by the IAC motor, located on top of the upper intake, under a plastic cover. The throttle body adjustment should not be necessary. Remove the air cleaner-to-upper intake tube. Remove the plastic cover over the IAC valve. Remove the IAC valve and look for gunk in its passages and the passages on the upper intake. Clean it out with some throttle body cleaner. Do the same for the thottle valve. Get an old toothbrush and scrub the hard gunk until it can be cleaned off. If possible, do the same to the IAC valve passages. Get some Mass airflow sensor grid cleaner and clean the grid of the Mass airflow sensor. It is located in the middle of the air cleaner-to-upper intake tube. Re-assemble it and give it a try.