no warning just, went bad one morning. went to go to work and the truck just sat there and would only crank over no start. they replaced the f.f. hsg and all was fine for about a year. this time it was tempermental and would hard start when engine was warm and only sometimes. changed filter and was a little better for about three weeks. then it started all over again. so back in it goes and another bad f.f. hsg and all is ok now. it seems that the check valve (stops fuel from going back into tank) hangs up. open and you lose your prime, closed and you get no fuel.

any one else have this problem with the f.f. hsg?

03 gmc duramax

your second time sounds more like bad injectors. Hard start when hot issues.

http://www.dieselplace.com/forum/showthread.php?t=146944&highlight=sparky1562

Having same problem, takes longer to start than normal, and will not start at all when warm unless I remove bleeder screw and prime it back up. Replaced fuel filter and even got a new bleeder screw, but still the same. Took it to the dealer, and they said there are no codes in the system. Said they tested my fuel, and the API was way too high! WTF! Said I should buy my fuel from a different source for awhile and see what happens. In the meantime, I guess I just get more practice priming her up. Only 60K miles on the truck, so I've got time, but I hate to spend it pumping the primer button! Will play there game for a couple of weeks and take it back. Hopefully, they will see its not the fuel and actually fix it then.

Having same problem, takes longer to start than normal, and will not start at all when warm unless I remove bleeder screw and prime it back up.

I doubt that any amount of priming would get it to start with bad injectors, from my experience and what I have read. Doubt it's fuel either. You might have vacuum leak in the fuel lines before the CP3 that only becomes a problem with heat. Search and read up on bad filter head assembly. Not saying it's not injectors, just don't recall any that started after re-priming.

Yup you can prime till christmas and it still wont start with bad injectors. Mine didnt leak fuel either, but had a high return rate and it wouldnt start at all no matter what warm or cold. I'd check return rates if all else fails. Mine didnt really smoke either.

Thanks for the info. Will tell them to check filter head assembly next trip in.