Recently, I put a new cooling fan in my jeep and wired it into the cab to a switch and an open fuse slot. The day after I did this I drove to my office and when I left to come home the jeep would not start...it DID turn over...I have changed out the following: fuel filter (there seems to be gas to the rail), crank sensor, spark plugs, ignition coil, computer (ECU), ASD relay, rotor...I was talking with a mechanic online yesterday and he was having me do some voltage readings but never gave me a definitive answer...there is power to the alternator but from there who knows what happens? All I know is that there is no power to the ignition coil wiring....thoughts? BTW- after I changed out the computer and the truck did not start I did return the computer and put the original back on....I need my truck!!!!

 

wow throwing money at a vehicle is not the method to fix stuff unless your fithly rich, then you probably wouldn't be driving an XJ

1st is fuel, use a fuel pressure gauge hooked up to the fule rail to make sure you are getting the correct pressure. Not enought pressure and the injectors wont fire. The camshaft position sensor also controls when the injectors fire and its in the dizzy

2nd is spark. pull a plug wire and stick a screw drive in it and hold to close to something metal. Have someone crank it over and if it has a spark then good. This is controlled by the crank position sensor.

3rd is air. Usually an idle air controller cleaning helps if it wont idle. did you try holding the gas pedal down alittle bit?

This method will focus you down to which system it is instead of mindlessly throwing parts at it.

 

I'd bet its the Crank Position Sensor

 

oh i missed the no power to ignition coil thing.

 

Is the temp sensor on the thermostat housing hooked up cause I know if that is disconnected it won't allow it to start as the ECU thinking the jeep is way too over heated and it shuts down the motor as a fail safe.

 

I recently changed out the temp sensor...could it be the wiring harness?? and if so where do I order one from??

 

Mine starts and runs fine with it disconnected. Was the only way it would run recently when the sensor failed.

-E