Hey if you are willing to help please email me with your thoughts. I have posted numerous times about an irratic idle and all I have gotten was smart *** remarks I thought we were all here to help each other.Well here's the prob- I have a 94 ex coupe d16z6 with cold air ,a hollowed out cat,basically a straight exhaust witha tsudo pipe,chikara header and all of a sudden after my car half *** warms up it surges at idle from 1000-3000 every so often but happens less when the lights are on then my thought when the coolant fan comes on it idles steady around 1200 so what could be the problem the dealer tried to tell me that it was the IAC valve I replaced that along with the map sensor off another d16 I am building but the problem persist.The only thing is when I disconnect the throttle position sensor when running it takes the idle to 3500 and stays there so could my prob be the tps? hit me back if ya can help any thoughts appreciated. Thanks mike ps also checked for vacum leaks and none present as everyone does not beleive or they beleive it is the answer

 

My dads sable does that, its an automatic and his car will spontaniously shoot up to like 2000 rpm and then when it is put in gear go down to 500. Its crazy. His entire electrical system is messed up though.