Hi all!

I have a '91 montero. It's idling really funny. It use to do this only occasionally but now it does it every time I put my car in park. It will rev up and down at a constant tempo staying between about 1000 and 1500 RPMs. When I tap the pedal, it will jump to 2000 and drop back down to the weird loping pattern. From what I have researched, this is due to a wonky TPS. If I am wrong, please let me know. I guess what I am asking is, is there a car that I can pull an identical TPS from, to avoid paying $200 for an OEM replacement? And where can I find out how to properly replace this?

Much thanks in advance!

 

Try cleaning your auxiliary air valve and throttle body first B4 you start replacing parts, and don't spray anything directly inside the throttle body because it will kill the TPS, just wet a rag with TB cleaner and go for it.

 

I agree with Maco35. Save your money and do a search in this forum for Idle Air Controller or IAC and poor idle and see what others have said about cleaning this device and the throttle body.

If you're handy with an ohmmeter I can send you the factory instructions for testing and adjusting the TPS (send me a PM with your e-mail address) however here is an important excerpt from that manual:

"Hint 1: The throtle position sensor signal is more important in the control of the automatic transmission than in the engine control. Shifting shock and other troubles will be the caused if this sensor is faulty"

Ron

 

Thanks for the help guys! I'm familiar with the throttle body, but could described where the auxiliary air valve is or what it looks like? And same for the IAC? I'll search up "poor idle" in the mean time.