My 96 Jeep cherokee 4L 6Cyl Has low RPM's in idle. Ill start it up and it runs Fine at first but then slowly starts to chug and get really low rpms... Checked all my spark plugs and cables. Do I have a Fuel issue? Will any kind of scanner tell me what kind of issue i am having. So lost and confused. Keep in mind I am very new to working on my cars at all. Just thought I should start doing this stuff on my 200K Mile jeep instead of paying $200 every month to have it fixed. Any thoughts?

 

In this order......................

1. Verify your battery. One of the most common causes of stalling is a marginal battery. The only accurate way to test your battery is with a LOAD TEST. Any parts store will do this for you for free.

2. Always review tuneup hardware when symptomatic. Champion copper plugs gapped to .035, new plug wires, distributor cap, rotor.

3. Clean your throttle body and idle air control. More on that below.

4. Still symptomatic after the above? Test both your throttle position sensor and your fuel pressure.
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The Idle Air Control (IAC) is mounted on the back of the throttle body. 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 moved in, the air control passage flows more air which raises the idle speed. When the valve plunger is moved out, 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.

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)

“Gently” wiggle out the IAC from the throttle body. Gasket 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 is best for this task. 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 itself, the butterfly valve inside of the throttle body and all associated linkage as long as you have things disassembled

Reinstall IAC and check idle quality

 

Thank you very much! I will look into all of this when i have time this weekend