I have a 1989 Jeep Cherokee Laredo 4X4. I had the same problem as you. Wouldn't start, no spark. It would usually start after a day or two if I parked it, which seemed kind of odd. I would take it to the repair shop and they would diagnose that the crank position sensor was defective, replace it and everything would be fine for a while then the same problem would return. After paying for several crank position sensors I found out that the plug where the crank position sensor plugs into the wiring wasn't making good contact. Jeeps of that era have a GM style plug and apparently this type of plug is notorious for losing contact. The easy way to tell if it is the plug is the next time it will not start. You can unplug the crank position sensor, blow in the plugs and reattach. Usually, just squeezing the the plug together would usually work. If it starts, you have your answer. You can then cut out the plug and hard wire the crank position sensor and it will eliminate the annoying problem forever. Ask your mechanic to show you where the crank position sensor plug is. It is easy to reach from the drivers side with the hood open as it is on top of the engine just behind the throttle body (towards the firewall). I can't tell you how much money I spent finding out this little piece of info and how common the problem is and how many crank position sensors are replaced when it is only a contact problem with the plug that connects the crank position sensor.
Wednesday, December 16th, 2009 AT 6:53 AM