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I was wondering if anyone would be able to tell me how to fix a problem with my '87 XJ. It has a non-HO 4.0 and an AW-5 tranny. Heres the story: Friday a week ago, i went to start my jeep after leaving it for about 16 hours in a parking lot. It would crank just like normal, but it never fired up. In the parking lot i got a good strong spark, and fuel in the fuel rail, but it would not start. If gas was poured in the intake then it would start. AAA towed it home. As far as i can tell i have sufficient pressure in the fuel rail, however i never tested it with gauge. The ignition was sparking well, so it was not that. I finally thought that the maybe the fuel injectors were not firing because they were not receiving the signal to do so. I decided to replace the CPS, since the computer does funky stuff when that is broken. Well, it didn’t work, even after re-setting the computer. I read an article that said the distributor had to be indexed exactly right so the sync controller inside the distributor would have the right relationship with the CPS. Ok, so i re-indexed my distributor, plugged in the connector to the sync control, and the re-connected my battery, and lo and behold it started. Not only did it start, it ran great, better than ever. But I forgot to tighten down the distributor and it got all out of wack and ran terrible. Then i re-indexed the distributor and tightened it down, it ran great once again. I drove it the next day for about 10 miles. Then I stopped for about 30 mins and drove it for another 3 miles. At that point, when accelerating from a red light, the engine quit with no warning whatsoever. It just stopped. I thought maybe I should reset the computer again. That didn’t work. I had it towed home. I replaced the distributor because I thought there might be a loose wire leading to the sync controller (Chrysler put out a bulletin saying that could happen). I made sure the distributor was indexed right. I let the computer reset, and tired to start it. Again, cranks but no fire up. Then I check the spark. No spark now! If I crank it for a while then smell the tail pipe, I smell gas fumes. I guess the injectors are working, then. I checked the coil, it test good but wont spark . So here is my list of possible problems:

If it is fuel related, then it could be the fuel pump, the fuel pump relay, the computer is bad, or loose wires somewhere.

If it is ignition related, the ignition control module, the computer is bad, or loose wires in the wiring harness.

So what do you guys think? What should i do? What causes a no spark situation? I'm thinking maybe ECM computer problem. That would explain why i can pin this thing down, right? Help if you can.


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