Nice to be under warranty, I asked about my warranty and GM dealer laughed. Ha! 110,000 miles and over 8 years old.
A few weeks back, my truck starting sending messages about replacing the fuel filter, so I ordered a FASS fuel system. It started to act like it is running out of fuel, so after a small incline or minor pull the engine would slow until enough fuel pressure builds back up. I thought for sure the FASS system would solve the problem.
I installed the FASS system and I clean/checked everything. I removed the tank and ensured that the pick system was not plugged. I installed FASS sump system. I did not find any problems with the fuel lines and tank. I install the FASS filter delete system at the original fuel conditioning module, which had no obvious problems. I reconnect everything and ensured that there was no leaks with a positive pressure at the fuel pressure/vacuum test port.
I reset the fuel filter life and started the truck. The same problem, the truck was running out of fuel after a minor pull. The engine light came on. I hooked up the scan tool and got P0087. I looked at the engine data on the scanned tool, the FPR2 (fuel pressure regulator valve on the fuel rail) was first to loose pressure, then the rail pressure would drop, and at the end the FPR1 would reduce. Based on this and some of my research at this forum I got concerned that maybe it is the CP4 pump failing.
First I removed the FRP2 (fuel pressure regulator valve) at the fuel rail and inspected it. No abnormal conditions, the valve was clean with no metal debris. Next i removed the FPR 1 (inlet metering valve) and inspected it. Again no abnormal conditions.
I order a new Exergy Inlet Metering Valve E05 10505 and I will reassemble everything, but what could be the problem? I know I am getting fuel to the CP4 pump via FASS.
Any help will be appreciated.
Thank you, g