2 issues, and wondering if they are related. I have only had the XJ (1996 Cherokee Sport 4 liter USA build spec) about 4 months. I love it. But it is doing a few things that have had it spending more time in the shop than on the road.

1) cutting out, it seems, mostly once it's warned up, the engine will cut out and back fire under acceleration. It is a low mileage (80,000 mi) vehicle, but looks like maintenance has been only marginal. I replaced the distributor, the wires and plugs, as well as fuel pump and filter. we also replaced the gas tank as it was dented and causing the siphon to not reach the bottom of the tank. This seemed to fix the problem temporarily, but it has returned. Generally around 2500+ rpm. feels a little like a rev limiter, quite violent.

2) overheating. It boiled over on me a while ago. found a bad hose, so i replaced it, then the water pump packed it in. replaced that. it continued to heat up, both on the highway and at idle it's running about 220 degrees if you leave it. the shop replaced the fan clutch and the radiator as well. We did a block check and found no combustion gasses in the cooling system, but it still overheats.

I love the truck, but I need it in my possession, not sitting in a repair shop. any thoughts?

 

not sure what kind of cooling system you have on a 96 model, but mine is an 87 and has a closed system. i changed a radiator hose a couple months ago and when i put water in the reservoir and started it up it just kept getting hot. then i read that for those systems you have to leave the cap off of the reservoir until the thermostat opens up, then it will pull the water into the system at which point you continue to add water or coolant while its running until the reservoir levels off at the correct amount. Again that may be different on a 96 model but thought i would at least give you something to take a look at.

 

Thanks, yes it's the same idea. but suggestions are always welcome. I'm getting them to look at a few other things along that line actually

 

classic symptoms of failing coil

verify the gauge reading with an infrared temperature gun on the thermostat housing. 96 still had the independent gauge sender at the rear of the head, they are failure prone

 

Will check coil. Temp sender good. i should have mentioned it is actually boiling the coolant if given enough time to heat up/

 

overheating on the highway usually indicates blocked radiator. You're not relying on fans, just wind through the rad

it could also be a clogged cat, would explain #1 and #2 both, however you would usually get loss of performance too

 

Yes we changed out the rad due to minor blockage, Still hot, I am wondering, if the rad may be too close to the A/C condenser. It's been hot here and using the A/C a fair bit. The cat is a possibility. I had a vehicle years ago where the guts were so loose that they would shift and block the exhaust. When it's choking and backfiring there is of course no power to speak of. It's not common, but I have seen intermittent cat issues. Perhaps because it's intermittent it's not setting a code.