I followed everyone's suggestions to total clean my throttle body on my 89 Cherokee 4.0. In fact I have a spare head and an entire engine setting here so I pulled one throttle off the head and supper cleaned it. I pulled all the parts off idle step motor, throttle sensor cleaned out every thing and all dirt blew out the passages with air, installed a new gasket and the problem dieing once in a while.

Now the jeep will not idle under 1200 to 1500 RPM in park and about 1000 RPM in gear. Thinking that I had made a mistake cleaning the first throttle plate, I pulled the current one and clean it up and install it. The same 1200 1700 RPM I am at a lost of what to try without purchasing an idle step motor. I have replace all the vacuum lines, have not vacuum leaks. I put a vacuum gauge on it the other day and it ran a steady 14-16 pounds.

Any ideas are welcome!

Thanks
Dennis

 

Have you tried spraying carb cleaner along the intake manifold? you may have an intake gasket leak if you do itll bog down.

 

After running it with a vacuum gauge and seeing very little movement in the gauge so I did not spray the intake with cleaner to check for a leak. It has no signs of a leak. No noise to speak of and no lack of power.

 

it dosent take much of one or you could buy a new IAC