ikatkoo

95 cherokee 4.0 auto. Ran great till recently it started idling like crap. And got to a point were it stalls out. And if im driveing and press break pedal and rpms drop under 1k it stalls out. Need help asap please.

xjmarc

Sounds a bit like a vacuum issue since the brakes effect it. Otherwise I'd say start by replacing the fuel filter, clogged one will cause idle issues.

Bustedback

If it runs good with your foot on the gas but stalls if you take your foot off, you need an idle air control motor. Very simple to replace and will cost around 50 bucks.

cruiser54

Ever do this?

Courtesy of TJWalker:
--------------------------------------------------------------------
The Idle Air Control (IAC) is mounted on the back of the throttle body. (front for 87-90) The valve controls the idle speed of the engine by controlling the amount of air flowing through the air control passage. It consists of a stepper motor that moves a pintle shaped plunger in and out of the air control passage. When the valve plunger is retracted, the air control passage flows more air which raises the idle speed. When the valve plunger is extended, the air control passage flows less air which lowers the idle speed. Over time and miles, the IAC can get carboned up which can have an adverse affect on idle quality. Cleaning the IAC may restore proper function and is an easy procedure to perform and good preventive maintenance so it is never a bad idea. This should be part of a normal tune-up procedure and whenever idle/stalling issues are present.

CLEANING THE JEEP 4.0 IDLE AIR CONTROL

Remove the air filter cover, associated hoses and the rubber boot that goes from the air filter cover to the throttle body. Remove the IAC with a Torx driver (2 bolts; one can be kind of hard to get to). On 91 and later, it may be easier to just remove the whole throttle body. Be sure to use a new throttle body to manifold gasket when reinstalling.

“Gently” wiggle out the IAC from the throttle body. Gasket/O-ring on the IAC can be re-used if it is not damaged

Clean the IAC with a spray can of throttle body cleaner; inexpensive and available at any place that sells auto parts. Throttle body cleaner is recommended rather than carburetor cleaner as it is less harsh, safe for throttle body coatings and oxygen sensors. Use cleaner, a rag and a toothbrush and or Q-Tips. Be gentle; don’t twist or pull on the pintle that protrudes from the IAC as it is fragile and you could damage it.

Thoroughly spray clean and flush where the IAC seats in the throttle body with the same spray cleaner

It is also a good idea to clean the entire throttle body bore itself, the butterfly valve inside of the throttle body and it’s edges, and all associated linkage as long as you have things disassembled

Revised 10-6-2014

dschappell

Doing this on the 99 xj today. Thanks for the write up.

ikatkoo

Well thats the thing. I have no vacume leaks iv looked. And IAC got cleaned and replaced but still doing it. No idea.

CCKen

How old is your Oxygen Sensor?

ikatkoo

Im not sure wana say 2 months?

cliffpenick

Just a thought do you hear a hissing sound when your press the brake pedal? If so your brake booster could be leaking vacuum causing the engine to not have the correct vacuum.

ikatkoo

Im not sure ill have to look but thank you hey another quick question how do you know when ur oil pump goes bad? My oil pressure gage is bad and wont work.

dukie564

your problem is most likely a faulty throttle position sensor

ikatkoo

So i replaced full throttle boddy and both sensors on it and changed o2 sensor and new vacume lines.. Still nothing and now it over heats even thou i put a new radiator in like 4 weeks ago.

dukie564

does it only happen when the truck is hot or cold, or all the time?

Firestorm500

Do you have any unexplained coolant loss?

ikatkoo

It happens all the time dosent matter if its cold or hot. And idk im almost sure i dont. But ill look.