Friend of mine has a 99 that will be running perfect then just shut down. Fuel pressure is good at 45. When broken no spark on coil lead. Then the next day it will start on first crank and run for 3 min then dead . No check engine light or codes. I have a good coil from one of my older jeeps going to try that.I wanted to swap out the distributor cam sensor because it seemed easy,....I cannot get the old one out of a distributor I had in the garage. The section where the wires are seem to be bonded to the distributor body at the "U" the rest is all loose. Can these not be changed without replacing the distributor. I also have a crank sensor but thats my last choice being such a pita to get to. Can those sensors go bad without throwing any codes? Thanks

 

Yep. That's normal. Dunno why that was not programmed to throw a code.


Actually, they aren't all that bad. Go in from below and behind. Use about 30" of extension. (Harbor Freight is your friend.) Use a u-joint on the end, and wrap it with one wrap of duct tape so it doesn't flop all over, but will still flex when you turn your ratchet. This is the best method I have found. Fuggedaboud going in from the top.

Your problem could be cam or crank sensor, or ASD relay. Those are the top three suspects, but the crank sensor is #1. Test it. When they go bad, they are heat sensitive.

Do NOT go cheap on the cam or crank sensors. Mopar only. Also sold under the NGK or NTK label. Nothing else. Every Jeep forum on the Internet is crowded with sad tales of aftermarket sensors being bad out of the box, or fa1iling within days or weeks or months.

 

Luckily it turned out to be easy fix...I had a new cps from my 92 but sadly it has round contacts where the 99 has square so no go there...I took out the coil it was bulging and cracked with rust and corrosion. Could not get it to spark with a 9v but I got mine to spark so I bought a new one...15 minutes it was running fantastic..Sometimes we get lucky..thanks for the help