1 year into the swap and now a fuel problem, got the granatelli fuel pump (255 lph), and Holley AFPR. Pressure chills at 40psi, soon as rev'd, pressure dies and if done too much, engine dies. put the stock FPR, engine revs and doesn't die but pressure definatly drops.

Tested friends lt1, chills at 40psi, when rev'd, goes to 50psi, and this is stock?!?!??! HELP!!!!

 

Do a quick check. Dissconnect the FPR vac line at idle and plug the vac line. The fuel pressure should go to about 60 PSI if I remember correctly. If it doesn't there is a sign the pump is bad.

Also check to see the fuel filter isn't plugged and the lines aren't kinked. Some people yank the plastic fuel line off the filter and it gets kinked a little behind the filter (output side of filter).

consider using an out of the tank pump that way you can replace it much easier.

BTW check to see if the fuel pressure stays up when the car is shut off. It should hold for a good long while. This could also be some help in determining the problem.

Also don't run in a lean condition for long, you could put a major hurt on the engine.