03 Duramax will not start

jlshermanjr

Member
Joined
Mar 10, 2007
Location
brevard nc
Started fine this morning, ran for about 1 minute and qiut. I changed the fuel filter, expecting jell, nothing, looked fine.I could not get the filter to prime. After work, I took off the filter and filled it, nothing. I expect it is the fuel pump. It has been surging at idle for a while. I feel it is the fuel pump. Where is the fuel pump? What do they cost? What do you all think?
thanks, johnny
 
It has had a long and good life. Set it aflame and push it out to sea, as the Vikings once did.
 
There is no "lift pump" on a duramax, just the CP3 that pulls fuel from the tank and through the filter in a vacuum, therefore if you have any air leak at all in the fuel system it cannot pull the fuel. The filter housings are known to develop hairline cracks, and the primer pump can develop a leak around its seal. An idea I found on dieselplace was to go to a local autoparts store, buy a NON vented gas cap that will fit your tank, and take a simple valve stem (like for a tire), and drill a hole in the gas cap, insert the valve stem, and use it to pressurize your tank to 4-5 psi, you should either hear air escaping, or see fuel squirting where the leak is.

Im actually tracking down a hard start issue when warm on my 03 duramax, but my fuel system primes just fine, I think its injectors, but want to be sure before the dealer.
 
jlshermanjr said:
Today I changed the fuel filter mounting assy. with the primer pump. WA-la it fixed it. Thank God.
Click to expand...

You beat me to it. I see this a lot at work. (I work for a GM/Hyundai Dealer)


GCncsuHD is correct on both accounts. There is no lift pump or intank pump. I have used shop air on a few trucks to pressurize the tank/lines until there is a sufficient amount of fuel comming from the bleeder on the filter housing. I simply put my blow off nozzle into the filler kneck with a shop rag wrapped around it and it works like a champ. :)
 
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