2003 Duramax will not start engine is hot without prime.
 

Having trouble restarting my 2003 Duramax when it has warmed up for 10 minutes or more.

Symptoms:


No codes

Starts cold with in seconds
Runs great
No smoke
No loss of power
No fuel in crankcase oil
Replaced fuel filter with in 100 miles
Replaced fuel filter/primer pump with in 100 miles
Will start when engine is hot after depressing primer pump 4 or 5 times (until firm)

Wife ran truck out of fuel 500 miles ago

Altinator went bad 600 miles ago.

Replaced one battery 450 miles ago

Any Ideas anyone

sounds like a bad cp3

My ignorance
What is a CP3?

the injector pump

Thanks for the suggestion.

How do you check out the CP3 Fuel pump regulator?

Engine idles fine

ECM lost VIN after altenator went bad and truck almost shut down when batteries went dead.

Replaced ECM

do you have a rail pressure guage

Ran the fuel pressure up with the computer.

Pressure did not drop off.

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Ned to get one.

the lift pump pressure or cp3 pressure

Don't know which pressure they were showing me at the GMC shop on the computer.

My curosity is why does the truck start great in the morning when the engine is cold and just crank over when it is hot?

i had a ford idi 7.3 that when it was cold would fire right up then when it got hot it would not start unless i used some kind of starting agent
when your wife ran it out of fuel your injector pump was ran dry no lube means alot of wear real quick and i think that is your issue