Jeep A little help.... DaveB maybe or some other jeep genius

[brokejeep]

Let me start with saying this is a problem with my brothers 1998 Cherokee. I will give as much information as I have and try and relay all pertinent information as I get it. My brother purchased a 1998 Cherokee some time ago and has run fine. While driving to work at HAFB the jeep started acting up. Eventually the jeep went into limp mode and he has been fighting it since. He has replaced all the sensors on the intake manifold new (used PCM) new distributor (used) tested replaced faulty injectors . We got the jeep running last night. When trying to rev the engine it back fires. My question is could it be caused by all the new sensors and such and the computer needs to relearn the tolerances coming in from the sensors???? Or is it we did not get the timing set perfect and that is causing the back fire and lack of throttle response? Thanks for any help or suggestions.

 

[DaveB]

I would guess that your timing is off. Set your motor at top dead center then check the rotor which should be pointing at cylinder one. If you have the newer style distributor with the multi coil pack you will need to find out how they time it (I haven't done one of those yet).

 

[skiboarder]

What about the timing chain. It may have worn out and jumped a tooth. Just a thought.

 

[gijohn40]

I was going to say timing chain as well... if you have a distributor take the cap off and turn the engine over by hand in one direction until the timing mark hits the timing numbers... once it gets towards the end stop and turn the engine the other way and watch how long it takes before the distributor starts to turn then look at the timing marks again and see how many degrees it took before the distributor turned. If its alot (10 or more) I would say your timing chain is shot