I bought a 96 Cherokee recently. As far as I can tell, it's all stock. Since I've had it it's always had a slight dieseling issue, but the timing is correct.
So the other day I noticed that the aux fan relay has a small piece of wire connecting two of the pegs and causing the aux fan to always run. Seeing no reason for that, I removed it, and for whatever reason the dieseling stopped. So the next time I went for a drive it got pretty hot, so I put it back. No more overheating, but the dieseling resumed. Anybody know what's causing these issues?