Jeep just quit, need help

First off Thanks for taking the time to look at this, The other day my wife was driving my 97 xj 4.0 auto, and it just shut off. Went to drag it home fond the coil wire was burned in two, at the coil, replaced the wire, and tested there was no spark, checked the fuses they were good, so I assumed the coil had gone bad so I replaced it yep you guessed it still nothing. Read on the forum it was more than likely my CPS so I replaced that. Still no spark. Any ideas will be greatly appreciated.

Are you able to communicate with the PCM via a scan tool? If you can, then that would eliminate the network or the PCM as a trouble spot. I had a similar issue last year and ended up having an internally shorted PCM. The PCM shorted and took down my network causing a crank, no start situation. When I connected a scan tool it would not connect or communicate due to the PCM short. If you're able to communicate via scan tool, then I would start removing sensors on 5v line to see if you can isolate a short.

I used the onboard check engine light flash style, at first it flashed three times, which I have no idea what that means, than it did the 5 and 5 which turned out to be end of code, tomorrow will start running down all the 5 volt wires and isolate them. Thanks for the ideas though I appreciate it.

You have to check the coil for voltage while it is cranking. It seems likely if your coil wire was fried (was it the dark green and orange wire?), the ASD relay also cooked and/or some other wiring or connector also overheated.

Don't trust your eyes when testing fuses, volt check both sides of the fuse.

I know this won't fix your immediate problem but my jeep kept burning out coils until I ran a new dedicated ground cable from battery negative to the engine block.( AC compressor bracket bolt).
The original strap ground from engine to chassis was deteriorated and once I did this my electronics seemed to be full of pep.
Quicker starts, better lights, more pep, etc.

I also decided to replace all the battery cables going to the PCM, starter, alt, everything just using grab bag different length cables from auto zone and I used the big brass connectors and have not a spot of corrosion in 2 years nor have I fried another coil.

Alright, let's start by determining that the coil has 12 volts to it. If you don't have 12 volts to create a magnetic field to create a spark, you won't have any. Now, is the computer switching the ground side to make and break the magnetic field to induce a high voltage spark. Electrical component testing rule number one I teach my students is never replace anything without confirming proper source voltage and ground.

I have 12 v on dark green wire going to coil, when trying to crank. I also checked to make sure I have 5 v going to cps tps map and cam position sensor? This is driving me crazy...

Ended up replacing the cam position sensor, she ran great for three days and then shut down doing the exact same thing. I'm at my wits end.

whjeep said:

I used the onboard check engine light flash style, at first it flashed three times, .

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1997 XJs have the OBDII diagnostic system, instead of flashing lights, you need a scanner to read the code.
Give it a try.

whjeep said:

Ended up replacing the cam position sensor, she ran great for three days and then shut down doing the exact same thing. I'm at my wits end.

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Replacing the Crankshaft PS with other than OE Jeep parts, your quality will be suspect. Especially electrical parts IMO.

Sorry I had posted the wrong year mine is a 96

I agree with lazyxj. 96 is OBDII, so if you put a code reader or scan tool on it, you should be able to retrieve the full PXXXX code, (if any codes are present) which is way more valuable than using the "key on, key off" technique.

I would absolutely start with that. Gotta see if there are any clues waiting for you in the way of codes. Sometimes a code is set just as a component fails so you won't know unless you scan the computer for codes.

What brand cam sensor did you use? The fact that you installed a new one and it ran fine for 3 days keeps that cam sensor in play. New parts can and do fail. More common than many would think. I almost exclusively use Mopar/Jeep engine management sensors, except for the oxygen sensors where NTK is original equipment and I can source NTK cheaper than Mopar and they are the same sensor.