2001 XJ daily driver headache

I hate all this electronic witchcraft....old Jeeps are much easier to diagnose and work on. My Cherokee died two weeks ago, it got me home but just barely. 100F day, driving home from work it starting idling really rough and stumbling around 2k RPM. It didn't overheat, stayed 200-210F the entire time which is normal. Wouldn't idle at all, hard starting. Bad CPS, got 180k+ out of the factory, only 30k out of this cheapo. Replaced it, starts fine and no longer misfiring but still idles a bit rough and pops through exhaust. Spent the last week testing everything, swapping out sensors, coils, parts, from my wife's Grand Cherokee just for a sanity check. Checked timing, injectors, compression, fuel pressure, vacuum leaks, O2 sensors, the usual. I did end up replacing the y-pipe min-cats, the factory one was running hot and partially clogged. New one installed yesterday, idled much better but still would pop through exhaust and stumble through acceleration. No codes at all which isn't helpful.

It sat for a few days and I started it up yesterday. Lots of white smoke for about 30 seconds, leaning towards head gasket at this point. Started tearing into the engine last night, lots of sludge built up in the intake and exhaust ports. Checked for cracks on the head, I have the infamous 0331 casting which is notorious for developing cracks. None found, engine very clean. No signs of oil/water mix in coolant or oil. If I had another daily driver or had the CJ-5 finished, I'd just tear everything out and do a complete rebuild. I have the parts laying around to do a stroker :drool:, but at this point I just need a car to drive. If I wasn't in the middle of purchasing a house, I'd go buy one. I had planned on finishing bodywork and painting the CJ-5, instead I get to work on this.

 

12 hours of wrenching and it runs!!!! Replaced mini-cats / y-pipe and cylinder head gasket.

 

Nice man, ya gotta love the 4.0.. hopefully everything is good now?

 

Yep, no problems. I was really considering doing a full rebuild but didn't have the spare cash to rebuild the transmission. This is also my daily driver. I don't want to yard out the drive train a second time. The motor still runs fine anyways, good compression and power.