93sport

First off, thank you in advance for any help you can provide. I have read through these forums many times to solve minor and major issues with my wife's Cherokee with great results.

Now, on to the latest issue: A little background. her jeep is a 93 sport 4.0 automatic. The engine went and her father decided to replace it. The engine he replaced it with was from a 98. other than an a very loud belt squeal we still have not fixed, it was running fine for about 2 weeks or so. Then the brakes went so the vehicle sat for about a week until we got around to replacing them.

Now the vehicle has a VERY bad hesitation while under part throttle. To the point it will rattle your fillings from the bucking. At idle it has a slight miss at times and when it starts bucking if you mash the throttle it will even out slightly and pull. their are no codes showing in the computer.

All plugs, wires, cap, rotor are new. When we pulled the plugs to check them three were not gapped right, but after re-gapping them and replacing the problem persists.

As I said the jeep ran fine for a week or so and only started doing this after sitting. I added some injector cleaner and filled the tank thinking it may be a bad fuel issue to no avail.

Thanks for any help.

95Cherokee

Mine has a hesitation under load as well, not as bad as yours though, it's the fuel pump going bad on mine.

and tell that girl she better get a printing press and start printing up some bills cause Cherokees require you shovel cash to them at a tremendous pace, I hope someone she knows is a mechanic.

mike37

check the harmonic balancer just to be sure it not bad and causing the vibration
just look at it and reve the motor look for any wobble