not getting enough fuel

[phaseoneracing]

i still cant get my car to run. the idle is going up and down and when the car is in gear it wants to die right out. i put vise grips on the fuel return line and it runs great. take them off right back to the way it was. any one have an idea what is wrong?

 

[Ahnubus_29]

Have you replaced your fuel filter or yor fuel pump lately. It sounds like the filter is clogged or the fuel pump isn't pushing enough fuel and the only way to build up enough fuel in the system is to restrict the fuel flow through the system by clamping the return line. You need to check your fuel pressure.

 

[phaseoneracing]

haven't changed the filter or pump. just had the head redone and replaced factory turbo with big 16g. i dont know if i have to upgrade the fuel pump. but it seems like that is what i should do to get more fuel??