likenew94stang

Ok guys...time for you all to come to the rescue once again.

My car at idle is surging a lot. When the car is cold it is worse than it is once warmed up, but it's still bad even warm.

The RPMS will surge between 500-900 and will even die once in a while.

There are no problems at ANY other time other than at idle.

I have a brand new Ford Motorcraft Throttle Position Sensor.

Any thoughts would be greatly appreciated!

ikeybmg

i think they all do it dude..lol. nah i know mine does it and alot of my friends do too. i have a 95 and id like to know what causes it too so please help this guy yall....

ZachW04Stang

Did you set the tps with a digital volt meter? BTW mine did the same thing, always has, I've replace iac, tps, o2 sensors, and cleand the salt and pepper shackers and nothing ever fixed it. I then replace my harmonic balancer, went away once I started it up with the new one. Theres a lot of things it could be, you just have to be patient and try to diagnos it without throwing parts at it.

fast95gt

Try adjusting your TPS.

PRO50SC

Have you tried cleaning the IAC.

stanglx2002

^^^ thats a good idea and also replace the pcv valve and screen they can cause idle problems too

90GTRagtop

I haven't had the problem, but I've read of a number of idle surges that were due to connection problems in the salt and pepper connectors. Cleaning IAC as mentioned previously is definitely a good idea. Also check for vacuum leaks, and pull the codes from the PCM to see if it has anything to tell you. Even if you're not getting a check engine light, there could be some codes.

PRO50SC

Could also check where the idle stop screw is at as well.