I have a 1990 with all the normal bolt ons, heads intake etc. It has been this way for several years with no problems. A few months ago it began ideling at variable speeds anywhere from normal to as much as 2500 rpms but only when it is fully warmed up. I have worked and checked things and can find nothing wrong and no codes. In desperation I took to the local Ford dealer where the new car tech guy played with it for the better part of 2 days with no results. Would anyone have any idea of what could possibly be wrong ?

 

vac leaks, O2 sensors, dirty maf

 

Who makes the etc bolt on? Im pretty sure you need to change your etc it probably came from china.

 

if what addermk2 says checks out fine , then make sure no codes exist , and if prob still occurs.....IAT sensor, check that and after that make sure IAC is clean and operational, koer test will verify IAC during low/high rpm test

 

http://www.youtube.com/watch?v=HJn-j...eature=related

the fact that there is an application process to allow people to have kids scares the hell out of me...