Reader Question: I just bought a 1996 Jeep Grand Cherokee 5.2L V8 and replaced the battery, fuel filter, spark plugs, and coolant hose clamps. It has 181k miles. It idles at the normal 1100-RPM cold and drops to about 500-600 RPMs warm.
Everything is fine while in park or while driving but if I sit in “D” drive with my foot on the brake, the RPMs drop to about 300 and shudder down to 200-100 and stalls out after about 30 sec.
Not real sure, what to look at but any advice would be great.
I would ask your mechanic to check your throttle body and idle control motor and clean them as needed.
Here is more about it, sorry no picture yet –
I would also look under the hood and listen for a hissing noise under the hood with the engine running for a possible vacuum leak like in a rubber vacuum hose on the engine.