ZJShane

So im new to the whole jeep thing but not to tinkering with cars. I bought my jeep last week knowing that it dies sometimes.Its a 97 Grand Cherokee 5.2. Other than that its a solid rig. So it has actually been driving pretty well but yesterday it died while warming up and hasnt started since. Im currently working throught the 12 things to do but i thought someone here might have some insight. I know the previous owner changed out the PCM and it was running fine but then suddenly died again. I swaped the relays around to see if the fuel pump was the issue but its turning on and i can smell gas when i keep cranking it over. I sprayed starting fluid into the TB and still wouldnt crank. I havent checked spark yet since i havent had much time to mess with it yet. But any ideas on where i should keep looking? Thanks

dave1123

Welcome to CF!

I'm thinking ignition coil breaking down when hot and now not working at all. JMHO however. Bad ignition wires can cause the coil to overheat from internal arcing.

The fact that you can smell fuel while cranking shows me the PCM, CPS and ASD relay are functioning.

ZJShane

Right on. I'll check that tonight. Do these things have ignition modules in the distributor like Chevys and what not? I know I've had a few of those get hot and rattle around then break.

ZJShane

So I took off the wire from the coil cleaned the connection and snapped it back on and it started right up. I'd been cranking it when I leave for work and then when I just got home and nothing. But right after I cleaned the coil connection it started. Weird. I'm sure it can't be that easy.

Edit: never mind it died again. But the fact that when I wiggle stuff it decides to start is progress.

jeepdewd

I had a hell of a time trying to pin point exactly what was happening when my jeep was dying out.... smelling gas? it only gets worse. So bad that you will blow out your exhaust system with detonations.

I had changed everything! PCM, ig coil, all my sensors on the intake... plugs wires, distrib... the list goes on


Here is what you need to do.

Go to a mechanic and tell them you want your harnesses (you have 3 of them plugged into your PCM) re-pined


They went in there and checked every wire. Found some broken ones and a bunch of pins that needed replaced.

I have not had a problem since


That work cost me about $1300, but it was worth every penny. I love my 97 ZJ



While your jeep is running try moving the harnesses and if the jeep dies out you (usually comes from the middle harness) you need some of those pins re-pinned.

If another clown tells you to just strap your harnesses down even tighter with a zip tie, dont bother wasting your time.


Best thing to do is find out in your area what the absolute best off-roading shop is for jeeps, call them and ask them who their recomendation is for best jeep mechanic in your area... They will tell you.

Here in Georgia, I called Southern Off Road Speciallists asked them that same question and got Team 1 automotive.
They Discoved the issue which was repinning the harnesses. I have not had a problem. Check this out if you like your jeep


Hope this helps

dave1123

Good point, Jeepdewd! A lot of PCMs have been saved by opening them up and resoldering the pin connections. It saves the cost and heartache of replacing the computer with just a little labor. One extreme case required a hairdryer to warm it up before the jeep would start. Same reason, bad solder joints.

That phone call thing must be a southern hospitality thing. Here in the northeast, you'd be lucky if they didn't hang up in you!

ZJShane

The pcm was just replaced and it was running great for awhile but just died again. It just cranks now. But seems like when I wiggle something random it will fire up for a minute then die again.

jeepdewd

Yes repin those harnesses!!!


BTW, I realized last night after my post that a lot of that $1300 went to a new oil pan and several oil seals. I cant remember what else I had done but that repining probably came down to around $400 maybe $300. Call a jeep mechanic and tell them you need a repin and start shopping for prices

ZJShane

That's good because I paid $900 for the whole jeep. So dumping $1300 into it wasn't gonna happen haha.

jeepdewd

I bought an 87 Cherokee 2 years ago for $800, it leaked oil like a *****... someone totaled my car while it was on the side of the highway... $6200 check from the insurance co.
I guess because American Largo was on the title it was worth way more


best 800 I have ever spent.

ZJShane

So an update. I pulled a spark plug to check spark and there was none. Jeep hasn't run in over a week now. Cranks just fine though. The plug was covered in fuel so I know the pump is working. I disconnected the battery and waited a bit thinking the pcm needs to reset to pretend to work again for five minutes. Reconnected the battery and nothing. Disconnected again and pulled a terrible wire job of off-road lights on the bumper out. Noticed the wiring went across the engine bay zip tired to random points. One of which was the main ground. It was also run straight to the battery with no fuse. So I ripped it all out reconnected the battery and it fired right up. I'm sure that wasn't the issue either but it's running fine again.