I need some help and advice from y'all. I've got a 98 xj 4.0, 4x4, AX15. I just got it back on the road and I've got a awful rattle in the top end. When I replaced all the gaskits I ended up pulling the rockers off cause the bridges were warped

 

I straighten the bridges out best I could. Was I supposed to tork them all at tdc? I keep throwing check engine light and it jerks and hops

 

I've put a new O2 sensor, camshaft/ distribor pick up, eBay map sensor and a eBay crankshaft sensor

 

Sooo what's the code set by the computer that causes the CEL?

 

It was P1391

 

P1391 Intermittent loss of CMP or CKP. Not related to any top-end looseness.

Was this code before or after you threw in cheap mystery sensors?

Have you checked over the wiring around the engine?

 

It started coming on after I put the cheep crankshaft sensor on. Before my old one burnt up it was hoping and jerking. The wiring is good around the motor

 

Your old CKP was burnt up??? How? Why was the wire not damaged?

 

My old clutch went out on me and I was about 3 miles from my house so from the heat of the clutch slipping melted the crankshaft sensor

 

Have the timing checked. I have the exact same code and my timing is off since I pulled my distributor and didn't get it put back in the exact spot. But jeep has the exact same symptoms and sure enough my timings off. So it wouldn't hurt to get it checked. Just my 2 cents

 

I just got to thinking about something. I had my flywheel resurfaced and when I pulled it off I didn't mark it. Could that be part of my problem? If it is then it don't add up. I can replace something and it will do great for a lil while then it starts the same ***** over again, its like a never ending cycle

 

I do think that I've got the top end rattle figured out and I'm looking at $100 to fix the damn thing so we'll see how this goes after I get off work today and with my luck its gonna cost me more than that......

 

Quick question. If I had an injector plug mixed up would it cause a P1391 code?

 

My jeep was throwing the same code after I pulled the distributor. I was getting "plug knock" from 1600rpm and up. Turns out my engine timing was off. Got it set yesterday and now there's no code nor plug knock. I would have your timing checked

 

When I rebuilt the engine I'd set the timing. It never threw a code and ran like a charm. I had a couple of friends tryin to help me figure out what was wrong with it. One was saying that it was a top end knock and the other one was sayin it was the bottom end. I stuck with my gut and pulled the serpentine belt off and checked my alternator. It was still charging but the bushings/bearings were FUBAR. Got a new alternator and she's back right. And I did buy a new crankshaft position sensor from the parts house and trashed the EBay one.