My 91 4.0L just quit going down the interstate one day. I've tried an new pump, filter, strainer, relay and it keeps blowing the fuel system ecu fuse. the only other thing I can think of is a bad ground or shorted out power lead.
Does anyone know a way to find/isolate these elec problems?
I've been on ramps in teh driveway for 3 weeks and cant take it any more!!!!
This has been covered many times on the jeepforum.
Your problem is probably electrical, and very possibly the ignition module under the wiper water bottle on the left front fender.
Look at your tachometer when your turning the engine over. Does the tach needle bounce up and down a little? If it doesn't, the module is giving you headaches. You may want to try to find one in a junkyard somewhere that you can plug in and try.
Also, if it's the module, you can sometimes push the vacumn advance lever back and forth a few times, and if you hear a faint clicking noise, you may be able to get the module to fire again.
Hope that helps. This advice comes from personal experience. Same thing happened to me
__________________ DOMINICAN STORM RIDERS JEEP CLUB, SD,RD, Member #1, 1990 Cherokee, 4.2, Autmatic, A/C, Stock.
It's my seventh jeep, had em' all my life, did all my 4 wheelin' on sand dunes. My jeep loves me.. right?
Racefan318, we had the same problem when we first purchased our '91 YJ. We checked all the wiring in the fuel electrical system, per the schematic. Ending up finding that the wires coming up from the O2 sensor, from the downtube on the exhaust pipe were shorting out aginst the block. Simple fix: replaced and shielded the four wires. Good luck !!!
I used the Chilton Jeep Wrangler/YJ 1987-94 Repair Manuel, Chilton #8535. I had to take the schematic to work and blow it up on the copier so thjat I could read it (getting older). The Haynes Repair Manual 1987-2000, # 50030, also has decent schematics. When blown up, I like the Chilton better. BTW racefan, I found my short purely by luck. .