2004 Jeep Grand Cherokee sometimes won't start.

[Beep Beep Jeep]

My 2004 Jeep Grand Cherokee sometimes won't start. When it happens, there's no crank, buzz or click. It is fully predictable when this happens. If I drive it a short distance--from one block to a little over a mile, and then turn it off for a few minutes, it won't start until I wait 30 minutes to an hour. This does not happen if I drive it several miles, and this is the only time it happens. It is NOT the battery, as it always starts fine otherwise. It is not the starter, as I have twice replaced it and it continues to happen. It happens although I shift to neutral, shift the 4WD to the lower gear. I cannot get it to start at these predictable times. No mechanic can figure this out. Does anyone have any idea? :shock: :evil: :???:

 

[JPNinPA]

Are there any codes?
In the first mile do you notice anything happening with the temperature or battery gage?
Same question when it doesn't start?

 

[Beep Beep Jeep]

There is nothing abnormal about the temperature or battery gauge. The temp is about 160-180, which appears normal for running only a short time. The battery remains constant at about 14 volts. There is no problem getting juice from the battery all of the rest of the time.

 

[JPNinPA]

When the CKP goes bad it will shut off the engine or not start it. Buy only OEM sensors.

There is a tsb for a heat shield on some years. The fuel lines above cyl 3 heat and vapor lock the fuel until it cools. But it would crank just not start.

I had an ifs die like this in my old f150 the brushes on the alternator wore down and were shorting. You could see the battery voltage bouncing up and down. If you shut it off while it was bouncing you could not start it back up right away.

Check and clean battery grounds. Good maintenance item.