87 XJ 4.0. Would randomly cut off while going down road. Have replaced crank sensor and every other electrical part. Cleaned all grounds. Now it will start right up sometimes, start up after 5-6 cranks, or not start at all but sounds like it wants to fire. Still will completely die riding down the road sometime. Could I have possibly got a bad crank sensor?

 

i had something similar with our 88 xj, ive replaced the crank shaft position sensor and that fixed it for a while then it started again and i had another look at the sensor and noticed the wire that leads to the sensor was sitting on the exhaust manifold and melting i guess it shorted somehow and a tie wrap getting the wire away from the exhaust fixed it for me.

marc

also checking the plug itself and see if its not bend inside ive read some aftermarket crank shaft position sensors have problems with the plug and some ppl even eliminate the plug completely and soldeer the wires directly to the original wiring of the jeep. (thats not what i would do tho i like to keep the wiring original)

 

Test it.

http://cruiser54.com/?p=50

Make sure the wiring isn't touching the exhaust.

 

After you test the CPS, note that the coil is only held with two screws and should show about 1 Ohm of resistance through the primary. Mine just did about exactly as you describe and I found over 2 ohms, swapped it to a coil with one ohm, and golden now.

 

one ohm? another site says open circuit!?
i bought one for my 00 and i get high readings on some pins.
drawings show ground, signal out, and either +5v or +12v supply?
i feel a magnetism in it with metal or a magnet. dont see much change when i move it.
so im lost! so far i have no trbl but id like to be ready
how should i test in the vehicle?, and my spare?

 

Out of your league here pal.

 

oh my God, you are killing me

 

found what i was looking for in section 8d of jeep svc manual,ill look at a test method . they give none!