SlickXJ

Hey everyone. A couple days ago, I was at a light on the highway. It turned green, and I started accelerating. Now I don't go like a bat out of hell, but I'm not a grandma either. All of a sudden, I noticed my check engine light was on. Nothing changed in the way the car ran, but the light popped on. When I got home, I topped off the fluids thinking maybe it detected they were a little low. I added a little oil since it was right below the add line, and let it sit overnight. Next morning when I was going to school, the check engine light wasn't on. On my way home from work about 8-10 hours later, it popped back on. So it seems it's going away when the car sits in the cold overnight, and throws the code when it gets to temp.

I've done a bit of research, and boy are there a lot of possibilities. Anywhere from the CKP/CEL to the distributor to the ECM. Now, all the people I see with the code report having a rough running engine. Mines completely fine as far as I can tell. I have a very very very slight rumble inbetween 1500 and 2000 RPM, but it smooths out. It doesn't feel like a misfire kind of rough. It's hard to explain.

What I'm trying to get at is what should I check first? I know to buy MOPAR only parts when it comes to sensors and the like. Should I just order a crank position sensor from the dealership and see if it fixes it? Would a dealership even help me with a cherokee this old? I got a key made there, but I don't know if they would sell parts for it.

If it helps, I have a multimeter since I'm a computer technician. I saw some people talking about checking for 5 volts on pins B and C or something along those lines, as well as checking for resistance. If it matters, the engine was rebuilt about 2.5k miles ago. If you need any more info, let me know because I want my cherokee to purr like a kitten for as long as possible

Radi

IIRC that code means you have an intermittent connection, usually the crank sensor. I'd start by disconnecting and cleaning all plugs and ground points under the hood, crank sensor first.

Roler

Intermittent loss of CMP (camshaft) or CPS (crankshaft) position sensor signal. You can test the CPS easier than the CMP, but I recently experienced that test results can give somewhat conflicting conclusions. Furthermore, the CPS is known to sometimes test ok when cold, but be faulty when warmed up.