[Bigg Ron]

Hi Everyone,

I changed the intake gaskets on my 99 2500 7.4 Vortec, due to a coolant leak, now it will not start, I have recheked basic timing and that looks good, however it cranks but will not fire at all, I have connected the scan tool and turned on the fuel pump relay, the pump runs hower I dont have any pressure at the fuel rail, I just changed the fuel filter as it was quite old, but still no pressure. I dont have any experience with this type of fuel injection, only throttle body from the 80's. Please lend a hand and help me get my daily runner going again.

Thank You

 

[murdog94]

is your Fuel Pressure Regulator dumping the fuel??

 

[Bigg Ron]

I'm currently preparing to remove the upper manifold and have a look at the fuel rail and pressure regulator, how would I test the regulator to verify if it is dumping the fuel. I have absolutly no pressue showing on the pressure gauge. This is the first time I have worked MPI vehicle, things are very tight and difficult to get to, I don't recall seeing an o-ring on the fuel lines that connect to the fuel rail, I wondering if it may have gotten pushed into the fuel rail. Any other help would be greatly appreciated.

Update, removed fuelrail test fuel pressure at the fuel line coming from the pump, it's reading 65 psi, reinstalled fuel rail and ran same test, now I have only 5 psi at the end of the fuel rail. Going to get new regulator.

Thanks
Bigg Ron

 

[Bigg Ron]

Good new, I got it running. I removed the fuel rail once again, purged the rail with nitrogen and seemed like it was clogged, I then tested the fuel regulator using nitrogen at the supply end and a pressure gauge at the test end, slowly apply pressure and watching the gauge, the pressure regulator would start dumping at 52 psi when vacuum was applied it would dump around 45 psi, I think the regulator was good, however knowing it would eventually fail I decided to replace the regulator, fuel pressure was good after that.

Next issue I had was getting the correct initial timing, I brought #1 TDC with dampener on 0, dropped the distributer in at #1 position, and it would try to start but it was still off, after searching the forums, I found information telling me to drop the distributer in on #8 when #1 piston was TDC, and the damn thing started, still can’t get my head around that, maybe some young tech can fill me in on how that works.

Thanks to everyone.

Bigg Ron