I just completed a fuel pressure check at the schrader valve b/c my car has been hesitating when accelerating with a load on the motor. I just completed a tune-up with opti, plugs, wires, coil, O2s, pcv and all was well until I put in the new delco fuel filter then the engine progressively got worse. The fuel pressure was as follows:

Ignition turned on, engine not running: Fuel pressure spikes to 44psi, settles at 42psi.

At Idle: 36psi

Simulated WOT (pulled vacuum line): 44psi

Actual WOT Run with load: 36psi-42psi proportionally with 2000-5000rpm run.

5th gear pull from 1700 rpm: 42psi.

I know on shbox's website he says the fuel pressure should stay between 41-47 psi, so is this reason enough to believe the fuel pump is the source of my problem.

P.S. I hooked the guage up again late last night, and it was reading 34 psi at idle and averaging 38 psi with just normal driving.

 

Sorry, just re-read shbox's website and it says 41-47psi when the lines are pressurized and the engine is not running. No need to reply.