Hey guys new to the 12 valve world, I recently bought a 1994 12 valve bone stock truck as a winter project. When I purchased this truck it ran very poor and you could not rev the motor past 2500 RPM it would just stay there, when trying to move in and out of the garage it would stall. So I purchased a new fuel filter deleted the fuel heater, cleaned pre filter, installed new overflow valve and Larry b's fuel pressure gauge. Primed the fuel filter by adding air into the fuel tank. have fuel at the low pressure side of injection pump. Cracked 3 injector lines was unable to get fuel when cranking motor over. Did not get any pressure on my gauge what is the proper psi at cranking over 10? Well I have 0. My question is it the lift pump is bad why did it run and start before? Do you guys think its a lift pump or plugged sock in the tank?