Well, I thought I heard a hissing noise by the fuel pressure regulator, but there was no visible leaks. Motor feels strong, when running, but has been starting kind of hard since the ls1 intake install. I put a gauge on the fuel rail to see what my pressure was, and I got 55psi idle, vacume off 65psi. But as soon as you turn the motor off the pressure drops to 0 psi. I am thinking my intank fuel pump may not be holding the pressure. I also have an inline 255 walbro pump. Do you think my intank pump is bad? Or is there a regulator issue? I figure the reg was ok if you pull the vac and preasure goes up.

 

I think I need a fuel preasure gauge in the truck to see what is happening in boost. I wonder if I am loosing preasure in boost?

 

Dude, you NEED one in the truck. With the amount boost you're running and the power your making, it's a must.

 

Hmmmm. Going to zero would make me think the FPR is on its last legs.

Definately get the fuel pressure gauge in the truck!

 

I agree. I prettu sure the pump doesn't hold pressure on the rail. The regulator does as far as I know??? Or at least it is the only other component that could I think.

 

Don't forget about the filter either. It's cheap and easy to eliminate that variable.

 

the in tank fuel pump does hold pressure. if not it will cause extended crank hard re starts

 

I have just changed the fuel filter, so should I changed the fuel preasure regulator? by the way thanks for any help you guys can give.

 

The fuel pressure regulator will not cause the fuel pressure to drop to 0psi. I would not put on a new regulator for this problem. I have been a GM service tech for 24 years if that helps.

 

The pump it is, thanks allscrewedup.