BillyBoy

Amen.

My coil pack was cracked... couldn't see it till I pulled it off... in pieces. ..

You can run a quick check by switching one of the plug wires for the one in the middle of the distributor. Then check again for spark... of course, a multi tester would be the way to go. And checking and changing your cap and wires once in a while is also good anyway.

Martlor13

man electrical issues suck haha.

J3ff3ry_J33pst3r

heh.
this kiddie meme stuff is like being at summer camp and 14 all over again + can go on all day/ evening but OP isn't gonna be helped by the interruption.
Irony? I talk all tough and experienced XJ owner with my," replace the ambiguously dead battery!' advice but after doing so yesterday, driving my XJ all over in "tough guy fixed it so must savor victory by lapping neighborhood" mode; wife goes to start it today and .....

it won't start...again.


i just realized mine wasn't pressurizing the fuel rail so just swapped with a new Fuel Pump relay . Gotta check. Doesn't explain 3-4 miles of perfect driving less than 24 hours ago (?) but it is what it is.

yeah, XJ electrical issues are about the lamest thing about Jeeps ever.

coreyt

truly, my original thread was less cohesive, as i spent more time systematically trouble shooting i wanted all my steps to be plainly stated. i'm certainly not trying to clog the forum with junk and i didnt think people would as easily follow my random reports

Martlor13

Yeah man my first post I agreed you should have just stuck with one thread and updated it as you progressed. The 2nd post I just started yanking your chain haha.wish I could help but you've covered what I would have done, and electrical isn't exactly my speciality haha. Hope you catch your gremlin man!

MWMahoneyJr

Man! What is the update? Power goes into one side of the coil, does it come out the other side?

coreyt

yes, i found a wiring diagram for the ignition system, I have the constant power from the ASD Relay to the coil packs but since i've verified the Coil Rail, CPS and PCM i am assuming I don't get the command to fire from the Coil Drivers in the PCM. I checked for continuity between all the sensors to the PCM as well as for ground and power. sure seems like it should be running.

the only potential issue i've found is a week ground at the PCM harness Clip 1 pin 4. if i check voltage from pin 4 to battery + i would expect to see 12V but its maybe 4v. I confirmed with my other jeep i get 12V. unfortunately I've removed and cleaned all the grounds.

coreyt

I made some solid Progress on the Jeep. Although the Camshaft position sensor shouldn't have any bearing on a no spark issue, we found there was a catastrophic failure of the sensor and distributer gear. basically the thing broke apart and pieces of metal and sensor were messing with the 5v supply. I went to a bone yard and picked up a new assembly and now the jeep starts and runs for about 3 seconds.

this doesn't have a smart key but it does seem like the computer is shutting the car down. anyone have any experience with this?

CCKen

If the PCM doesn't see a valid crankshaft rotation signal from the CPS within 2 seconds it will terminate the ASD and fuel injection system.

nujeepguy

threads like this put the fear back in me,"worry wort", the reason i wont drive far from home.

Martlor13

I think you need to stop reading threads then hahaha

coreyt

sure sounds like the ticket except i can keep it going via starter fluid for maybe 8 more seconds. if the computer shut off the ASD wouldn't it stop the plugs from firing as well?

second, i replaced the Crank sensor with one known to be working, I also tested the plug for 5v and connectivity on the ground and signal wires to the PCM harness. is there another good way to test the CPS is sending a signal.

coreyt

ok, so i think i've some to final resolution on this issue, turns out when the Crank position sensor and synchronizer gear broke they created a short that also killed my computer. a quick stop to the boneyard for a 30.00 computer (Same exact part number) 635ag was a plug and play fix for the car.

CCKen

Good work, but....


It's a Jeep not a car.