88 Cherokee surging/stuck idle

[Jewel]

I have a 1988 Cherokee Laredo Jeep (4.0 automatic). The idle surges and then gets stuck around 1500 RPMs/2000 RPMs and stays there while driving. My Jeep will drive itself. This morning I cleaned out the throttle body, linkage, carbon out of the idle air control motor and cleaned off the throttle position sensor. Then I took it for a drive and it did not change the performance. I am a single woman whose learned how to work on her own Jeep. I am so frustrated. My Jeep will not idle properly at a stop light/sign and when I come to a stop I fight the gas and the brake. Please help me!!!

	Throttle position sensor A throttle position sensor (TPS) is a sensor used to monitor the position of the throttle in an internal combustion engine. The sensor is usually located on the butterfly spindle so that it can directly monitor the position of the butterfly throttle valve. The sensor is usually a potentiometer and therefore provides a variable resistance dependent upon the position of the butterfly valve (and hence throttle position). The sensor signal is used by the Engine Control Unit (ECU) as an input to its control system. The ignition timing and fuel injection timing (and potentially other parameters) are altered depending upon the position of the throttle, and also depending on the rate of change of that position. For example, in fuel injected engines, in order to avoid stalling, extra fuel may be injected if the throttle is opened rapidly (mimicking the accelerator pump of carburetor systems).

[black87yj]

i know this sounds too simple, but look at the carpet around the pedal ? if its sticking at a certain spot (or rpm) perhaps its not the linkage but a hang up. mats old carpet and debris sometimes or a bend in the pedal lever ?

[Jewel]

Thank you for your response regarding my Jeep. I even went and replaced my sensor and idle speed control motor and my jeep did not respond. Just the other day I crawled under my Jeep and notice how much oil and dirt was up around my transmission and I notice some linkage I missed cleaning. I cleaned that linkage around the transmission and the idle came back to normal. I can't believe I had this problem for nearly a year. I did a tune up and my Jeep sounds good and responds well. I think it had to do with this heavy corroded dirt preventing shifting/sticking.

Peace be with you, Jewel

[Saurian]

It's those things that you really wouldn't think of that get you... On my buddy's Mustang, it was doing the same thing, he was thinking vacuum leak, broken cable, all kinds of things, it would want to fly down the road at red lights... A little WD40 around the throttle body where the cable moved, problem totally solved... Glad you got your Jeep up and running properly, and welcome to Jeepz, hope you stick around.