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-   -   4.7 Will crank over, but will not start (http://www.jeepgarage.org/f203/4-7-will-crank-over-but-will-not-start-59715.html)

cblowers 05-08-2013 07:45 PM

4.7 Will crank over, but will not start
 
I have a 2004 GC Limited 4.7 The ole girl will crank over but will not start. Seemed like a fuel problem to me..........but fuel pump kicked on, I heard it. I did not check shrader valve for pressure. 10 Disc changer in rear cycled on and off several times and dash/headlights flashed. Jeep fired right up!

The next time it happened almost the exact same signs and symptoms........and after about 10 minutes (i feared burning up the starter) It fired up again.

This morning it happened again but WOULD NOT start. After a few expletives i disconnected the battery and reconnected it. It started right up then. What could cause this? Any Ideas???

Crank sensor? Or is there another relay or solenoid that could lead to the enging cranking fine but not starting?

Hacksaw 05-08-2013 07:56 PM

Crank Position Sensor, Throttle Position Sensor.

Think Outside ! ...No Box Required

cblowers 05-08-2013 08:13 PM

Re: 4.7 Will crank over, but will not start
 
I have read a little on the crank sensor. It could be that.......just didn't sound right to me. Replaced the TPS 3 months ago due to shifting problems. That fixed that issue. now this........

THANK YOU FOR THE REPLY!!!!!

Frango100 05-08-2013 08:37 PM

Re: 4.7 Will crank over, but will not start
 
Welcome to the garage.
That the fuel pump kicks on is no guarantee that you have fuel. A clogged fuel filter or not good working fuel pressure regulator could prevent fuel going to the rail. So good to check if you have pressure there after priming it once. (take care that fuel can come out under high pressure, so use a rag to catch the spill)
Crank sensor or cam sensor are well known to give problems you related. Check engine light is not on? Just to be sure, do the key dance to see if any fault code is set: ignition switch off/on three times and leave in on at the third time. The odometer will show DONE when all ok, or a fault code.

cblowers 05-08-2013 08:48 PM

Re: 4.7 Will crank over, but will not start
 
Thanks for the welcome and i will check the filter and i'll get a guage tomorrow. I work at a equipment dealership. unfortuneately i know more about the diesels than my own gasser. Sensors seem to the the main prob in the GC line. I hope to have more discussions with ya!

I love the pic BTW

Frango100 05-08-2013 09:32 PM

Re: 4.7 Will crank over, but will not start
 
Ofcourse you could measure the exact fuel pressure, but it should be enough for now to just check if fuel under pressure comes out of the schrader valve.
You could also check the auto shuttdown relay in the PDC under the hood. For trouble shooting purposes you could swap it with the TCM relay, which is in the same PDC as well. Also check out the fuses.

cblowers 05-13-2013 08:03 PM

Re: 4.7 Will crank over, but will not start
 
Grand has not acted up since my last post. Checked fuel pressure and everything related. No problems. I tested my crank and cam sensor.......both looked good on my fluke. So I'm at a loss of what to do until she won't start again.

Are there any mods you can do to take the swaying motion out of her while you are driving? It needs tightened up so I can cruize these back country roads and let the horses sing. It really sways coming in and going out of corners.

Frango100 05-13-2013 08:45 PM

Re: 4.7 Will crank over, but will not start
 
Some bilstein shocks and stiffer swaybars (Addco) seem to make a world of difference in the handling.
Did you check by the way for any fault code set?


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