I just picked up a nice cherokee for a friend of mine who is going through a rough time. I figured these things are relatively indestructible and dead reliable. It's a 1999 sport with the 4.0L I6. I got it for a song because the guy said it had a hot start issue. hot start has now turned into no start.

At first, I though it was the crank angle sensor, which is super common. Replaced that. started up, warmed up, then sputtered and died. Alright, try the coil because is has cracks on it. Started up, ran great, put it on trailer to get it home (solo operation picking it up) got it home and won;t start again.

It has spark, verified across several cylinders, nice blue, bright spark that you can hear snapping. It has fuel, I pulled several spark plugs and they were wet. and it has compression.

It will not run on starting fluid! which is surprising as hell. It usually needs several hours to cool down enough to re-start. when it does restart, it acts like it pops off on one cylinder, then another and another until its running fine and clears the fouled plugs and runs great..... for about 10 minutes, then stalls out and won't restart.

so, any ideas? checked the TPS and the MAP, both tested good. not throwing ANY codes.