When i crank the car cold it will hold 7 psi. After it warms up it drops to around 4 psi. I was thinking maby vapor lock but my fuel lines dont run near anything realy hot. They get close to the block but i dont think it will get hot enough to boil fuel.

The problems started with i put the new motor in. Mosly stock just 10.2 comp, a small 268 cam, 416 heads with a valve job and gasket matched, holley contender intake, my spare 750 carter afb, and hedman headers.

I am runing a stock mechanical fuel pump, with a holley red as a pusher pump (did not help at all). Put new filters 9 months ago.

 

i had a similer problem and it endid up being a problem in the tank. there was rust in the tank and it pluged the pickup tube. same condishions, it would start up for a few secs...than lose fuel pressure and die. you may want to check the tank. any holes it it? this would be a sere sign you have a problem.

 

Problem fixed, thx anyways. Ended up redoing my pickup and changing all filters.