completely stumped

Wondering if your timing chain has jumped it could be the problem. Because I've had a similar problem on a non Jeep vehicle and it was due to the timing chain jumping.

the fact that it stays running, running smooth as a tesla for 10-15 seconds maybe more has me puzzled. If it had jumped the chain would it still run well for that long? I'll have to pry some more... keep you posted!

jcarrera said:

the fact that it stays running, running smooth as a tesla for 10-15 seconds maybe more has me puzzled. If it had jumped the chain would it still run well for that long? I'll have to pry some more... keep you posted!

Click to expand...

Ain't the chain.

jcarrera said:

one bottle of bg44k and a replacement ECM (488) and still no dice. Will run smooth for a few seconds and will die. if any throttle is applied it sputters, back fires and dies.... cleaned all grounds to bright shiny metal, they might as well be chromed at this point.

Click to expand...

You could still have a resistance problem with a damaged wire. This was why I replaced the last several inches on a couple of my ground wires that showed damage near the ends.

A wiring resistance problem would be consistent with your problem. A wire that already has a resistance problem gets hotter and the resistance increases. The challenge is finding that particular wire. I had one that took me months to find. It was on my '90 GTA, and the problem was with a single injector that would short out internally and pull down the entire bank (batch fire). And of course it only did this when I had driven away from home. I found that one by disconnecting the injector to test with a noid light.

Having gone through all your grounds, did you notice any wires that felt hard and inflexible? That is a sign of excessive heat. I would start by checking all the ignition related wires. Make sure they are still flexible and that there is no damage to the insulation. Move wiring around temporarily just to see if being pulled away from something solves your problem. (BTW, have you made sure your coil wire is not compromised in any way? Random thought, can't keep track of what all you have/haven't done. The coil wire is one of those I would be moving for testing purposes.)

I would also closely inspect any places where wires get close to metal. Again, inspect the insulation.

Another place to look is fuses and relays. Pull them one at a time and inspect the spade terminals. They should be relatively clean. A brass wire brush on any that have surface corrosion would be good.

I would also look under the dash. Has anyone ever spliced into the "ignition on" circuit for the addition of aftermarket stereo equipment, an alarm or some other such thing? I never trust any of those people's crimp connections. Don't go tugging on any of those wires unless you are prepared to make some splice repairs, but if you find suspect wiring down there arm yourself with the right tools and go after those connections. (Right tools in my world require solder and heat shrink.)

It sounds to me like you have something electrical that is heating up quickly and probably shorting out, or at least providing such a high resistance that something ceases to function. It could be in the vehicle wiring, or it could be internal to a component (like my fuel injector). Besides the wiring check, I would be doing everything possible to monitor systems functions during failure. Watch fuel pressure and whatever you can manage to watch on a scan tool. Keep searching for clues. And let us know what you find.

The injector wires are color-coded for proper sequence of injector firing. Are you sure the correct colored wire is connected to the correct injector?

Best regards,

CJR

Cruiser54; I sure hope it ain't, even though Im getting use to wrenching on this thing, It would suck to have to tear the front end apart again.

Anak; I've been trying to go at it from all directions and I agree i have to be more systematic about this. Im going to have a closer look under the dash, some one did manage to install an aftermarket stereo which I hate to admit is always worrisome.

CJR; I had labeled the injectors before taking them off the old engine but you never know your suggestion is definitely worth looking at. I am going to look up the firing sequence for the injectors and report back

Thank you all, I'll keep you posted

Does a 92 still have the ballast resistor on the drivers fender? If that's damaged that could explain dying shortly after starting. Unplug the O2 sensor and see if that changes anything.

lawsoncl said:

Does a 92 still have the ballast resistor on the drivers fender? If that's damaged that could explain dying shortly after starting. Unplug the O2 sensor and see if that changes anything.

Click to expand...

What he said.

Kind of sounds like fuel starvation.

And I may have missed it in a previous post, check the fuel filter. Gas can turn to jelly if it sits long enough. Remove the fuel filter, have some extra hose ready just in case, blow through it backwards and see what comes out.

Check and see if you get the same fuel pressure with it running or does the needle drop just before it quits?

After hours of disconnecting polishing and reconnecting wires, and just as I was about to install a new distributor and NSS ($450 big ones). I decided to also pull the new CPS I installed a few weeks ago to test it for resistance... Sure enough, there it was staring me in the face. The corrugated plastic wire insulator has a spot shinnier and smoother than the rest of the plastic but it is not yet melted. The wires inside have the same shiny appearance on a small 2" long section.

I have the cps wiring routed as far away from the header as possible but the heat somehow still affects it. I improvised a small heat shield out of welding glove with the silver lining material and voila, jeep stays running smooth. I even managed to go for a 20 minute drive without further problems (well not quite, the 5amp fuse for the instrument lights blew out again)

To all those who chimed in with suggestions, thank you for keeping me in the hunt. I feel I have learned quite a bit and oddly enough I somehow like this car more than when I dragged it home. Thank You all!!!