Engine Mechanical problem
1995 Jeep Laredo 6 cyl Four Wheel Drive Automatic 224000 miles
Okay, this one is stumping my feeble mechanical abilities.
It all started with a bad idle. ZJ 4.0 would run fine for days and days then while sitting at a light, the idle would dip to 250 and go back up. Only to not do it again for a day or so.
Then, one day, I was at a Mall, got in the Jeep to start it and it wouldn't start. Turned over fine, but wouldn't fire. I put it in neutral, tried again and it started.
Then, it happened again, this time neutral didn't work. I played with the relays and it started.
Then it happened again, this time the relays made no difference. I just had to wait and try it periodically. Then it started.
Still thinking it was the relays, I replaced the fuel pump relay and the ASD relay. I also replaced the Throttle Positioning Sensor just for kicks.
But, it happened again. And again. And again.
Then I started noticing that while driving, it would jerk like it was going to die.
And then, tonight, driving home. It happened. On the freeway, a section with no shoulder, the RPMs went to zero, I kept on the gas pedal and the RPMs jumped to 2000 then fell back to zero, I pumped the gas and nothing, but I kept on it and it fired again but then back to zero, this happened a couple more times before completely dieing. I managed to coast long enough with the hazards on to make it to a safe shoulder.
I checked the relays. I checked the fuses. I used my iphone to search the forums. I checked the spark plugs to see if they were firing. Nothing seemed wrong.
And then she started again. I drove her home and the rig died three more times, each time I would have to wait and little bit, try it again and start it up.
I also replaced the plugs, wires and the cap & rotor.
So that's my story. Your insight is most appreciated!
Friday, January 29th, 2010 AT 1:48 AM