Attention: TDR Forum Junkies 
Hello fellas,
I have a 98.5 with 360,000 miles and currently a Fass HPFP that has around 150,000 miles. Today it started to starve all of a sudden. I looked up at my Pyrol guage and I have 5 psi. I pull over and shut it down and poped the hood. Filter can is ok with no leaks. Examined the entire underneath and still no leaks. I turn the key on and it pumps up to around ten psi. Started it and the pressure drops again. The Fass pump is running. I can hear it well. I get it home and hot wire the pump to get it up to the normal 15 psi and start it. The pressure drops again but faster. I pump it up again and turn the pump off without running the truck and the pressure still falls. Still no fuel leakage anywhere. Now I put external pressure gauge on the fuel filter canister mounted on the side of the motor. Turn on the pump and it comes right up to 16psi, then turn the pump off and pressure drops to zero. As well, I notice that the can empties out when it starves (obviously) and it takes 20 or 30 seconds for it to fill back up. ( by checking the drain out valve on the can) It seems that the pump is not holding the pressure in the system or the pump cannot sustain the requirement from the VP44. Does any of this make any sense? Is there possibly a check valve within the pump that has failed? Or is the pump failing itself? Any thoughts are appreciated. Thank you.
I have a 98.5 with 360,000 miles and currently a Fass HPFP that has around 150,000 miles. Today it started to starve all of a sudden. I looked up at my Pyrol guage and I have 5 psi. I pull over and shut it down and poped the hood. Filter can is ok with no leaks. Examined the entire underneath and still no leaks. I turn the key on and it pumps up to around ten psi. Started it and the pressure drops again. The Fass pump is running. I can hear it well. I get it home and hot wire the pump to get it up to the normal 15 psi and start it. The pressure drops again but faster. I pump it up again and turn the pump off without running the truck and the pressure still falls. Still no fuel leakage anywhere. Now I put external pressure gauge on the fuel filter canister mounted on the side of the motor. Turn on the pump and it comes right up to 16psi, then turn the pump off and pressure drops to zero. As well, I notice that the can empties out when it starves (obviously) and it takes 20 or 30 seconds for it to fill back up. ( by checking the drain out valve on the can) It seems that the pump is not holding the pressure in the system or the pump cannot sustain the requirement from the VP44. Does any of this make any sense? Is there possibly a check valve within the pump that has failed? Or is the pump failing itself? Any thoughts are appreciated. Thank you.
