ChickenScreamer94

OK guys, let me tell youwhat is going on. My car surges at idle when it has ran for more then thirty mins and has sat in traffic. IT is not a miss, just a surge. It only happen at idle, but had a hint of it a 1500 rpm the other day. It goes through all the gears smoothly up right up redline. So far i have replace the IAT and IAC motor. After i replaced the IAC it got better, but then came back, just not as bad. Oh yeah, my waterpump weephole is not leaking, so opti is very unlikely IMO. 55k miles on car.

I know this is a heat related problem. It really becomes present on hot afternoons in traffic. Any ideas on other sensors to check out?

I was thinking about relocation of the IAT since it corrected the problem for a couple of days. I am a little nervous about hacking the wiring and the 40 dollar jet kit is too expensive, but i am willing to do it. I also heard the coolant temp sensor can go bad, how do i go about replacing that?

Basically any ideas are welcome, but after doing a huge search it seems like it may be hopeless

PatriotTA

Replace your TPS (throttle position sensor). I had the same exact problem (not in an f-body though). I replaced the IAC, and it got better, but not 100%. So I replaced the TPS and cleaned the shaft the butterfly sits on and the problem was gone. I'd definitely swap out the TPS, its only about $20 and it fixed my problem completely. As for relocating the IAT, I wouldn't worry about it. On '94s and up, the IAT isn't really used that much during normal operation, since the ECM just reads the MAF sensor.

ChickenScreamer94

ok, sounds good, i never thought about that one. It is a part exposed to heat i guess (maybe the internal tolerances vary with temp?). I still have this feeling the IAT is a player in this or possibly the MAF sensor, but i will have to finagle with these things to figure it out...

What was the make of the vehichle you are talking about Patriot TA? Was it a GM? What year?

More guesses? I am thinking the coil and might possibly do the ICM mod since washers are dirt cheap.

I would scan my car and get it over with but they are kinda expensive. I always wanted a scanmaster but my 17 year old budget wont quite allow for one yet.

MentalCaseOne

For the Coolant sensor question

Its only about 9 dollars for the Coolant temp Sensor. Drain your radiator, take old one off put new one in. Its located on the Waterpump.

Since its so cheap it may be a good idea to change it. It seldom goes bad though. I am more inclined to think your problem could be something else.


Marvi