03 Duramax 6.6L wont start any IDEAS!!!!!

[Duramax_89]

Truck began hesitating at first but would eventually start and has progressively gotten worse and now will not start. when this began i would continue trying to start the truck until the battery's eventually died, but here's the catch when i hooked cables to it, it would fire right up. i have replaced the battery's, the alternator and all 8 glow plugs. The truck starts fine in the mornings but if it gets hot and i turn the truck off it will not fire, until i hook jumper cables to it both battery's are good reading 13+ volts each any ideas.

 

[blk smoke lb7]

Make sure you have a good ground.check to make sure it's not loose or corroded at the battery and at the block.

 

[o4dirtymax]

Are you using the volt meter on the instrument cluster or a portable meter?

All you're doing with the jumper cables is essentially putting more power through the battery then to starter so it sounds like somewhere you're losing juice. If you have a voltmeter, (not the meter on your instrument cluster), test the batteries individually while the truck is running, and when it is turned off. Ensure your new alternator is in fact charging using your meter. If it is charging, disconnect both batteries, let the truck sit overnight, then test each battery individually. Individually because these batteries are in parallel and simply "combine". If one of your batteries is bad, it will drain the other one so be sure to test them individually.

 

[Duramax_89]

Update

Are you using the volt meter on the instrument cluster or a portable meter?

All you're doing with the jumper cables is essentially putting more power through the battery then to starter so it sounds like somewhere you're losing juice. If you have a voltmeter, (not the meter on your instrument cluster), test the batteries individually while the truck is running, and when it is turned off. Ensure your new alternator is in fact charging using your meter. If it is charging, disconnect both batteries, let the truck sit overnight, then test each battery individually. Individually because these batteries are in parallel and simply "combine". If one of your batteries is bad, it will drain the other one so be sure to test them individually.

Heres an update, after replacing the glow plugs and that not resolving the issue i replaced the o rings in the fuel water separator housing this seemed to do the trick for about a week, i left to go to lunch the truck started fine drove a few miles down the highway ran fine after eating my meal i went to leave and the truck would not start. The truck turns over fine but would not fire, primed the fuel still wouldn't a buddy of mine came to help out we hooked up the jumper cables and she fired right up drove it straight to the shop and turns out my fuel pressure regulator was bad, replaced it hoping this would fix the problem picked the truck up yesterday started fine drove it about 10+ miles stopped at a gas station was inside for about 10min. (long line and slow cashier) went to leave wouldn't fire, turning over fine no fire. once again hooked cables to it fires right up, drove to the house turned the truck off hooked the battery tester up to both batteries separately 13 volts each turn the ignition on drops to 11 volts each and holds while turning over the ignition and of course she fired up while testing each battery also waited about 30min and tested again and she fired up but later that night she began to not fire again hook cables up and fire right up. I'm at a loss here not sure what it could be and it seems no one has ever herd of this problem.

 

[blk smoke lb7]

Drive it to a autozone or adavanced auto and have a battery and crank test done.Check your grounds to the frame and to the side of the block and make sure thay are conected properly and not corroded.

Oh and make sure you bring a set of jumper cables to make sure you can get back home

 

[Duramax_89]

Update on this issue Truck is now running!!!!!! But....

Finally found diesel fuel in my oil (on the dip stick) so I replaced all injectors and haven't had a problem out of it. Other than "pump rub" in my transfer case waiting on the arrival of the new one should be here beginning of next week. Gotta love it.

 

[Kappa9012]

glad you found the issue. Sometimes these things take forever to show themselves.