my jeep once a day, starts vibrating badly, while doing that my rpm needle starts to waver back and forth quickly in park. When you put it into drive and start to step on the gas. Thier is random hesitaition on the gas, the hesitaition is the engine is going but randomly the gas gets to the engine and goes. Its hard to describe. When driving the mufffeler sounds like its back firing when gas gets to it, crackleing and poping from the muffller. when i go below about 15 mph the idol goes below 1000 rpm and will some times quit. i am deeply anoid about this problem. Would it happen to be a bad or old fuel pump, or anything to do with my fuel. when my car does quit the needle on rpm wobbles and you can hear the fuel pump going till I shut my car off fully, i searched for other likly problems and clostest thing was a steering dampener, and I dont believe it is the IAC. please help and thanks
fuel pump/ oxegen sencor on 1994 Jeep Grand Cherokee
by asdh04 in Mound, MN on July 05, 2009
ANSWER by dandd on July 05, 2009
This sounds like you have a leaking exhaust manifold on your 6 cyl Jeep. When this happens, the Jeeps tend to run very erratically, surge in park or neutral and hesitate and die on acceleration. This is because the Oxygen sensor is in the exhaust manifold, and , usually the manifold is cracking which lets fresh air hit the sensor, causing the Jeep to run really bad and sound loud as well. Have some one verify this. To replace the manifold, it is 4 hours plus the part. You can get them from after market suppliers which are much cheaper than the factory units.