I have a 2012 BF50D S#BBEJ 1012938 that will entergize the H/P fuel pump with the key on & I can achieve 40 psi. When I start the engine, it will run until the fuel pressure drops to about 20psi. I replaced the H/P fuel pump due to stuck in the VST & cleaned. I bought a factory manual to find what components control it. With a test light & DC volt meter. the pos. side is good to the pump. The neg. side gets a 2 sec. completion to the pump. It drops when the engine is started. Cleaned all connections with electronic cleaner & applied Dielectric grease. Hooked up the motor to a separate battery & cables to insure a strong 12v. The manual states that the ECU controls the neg. (blk/white) wire with inputs from the (2) crank & (1) cam sensors. There are no alarms active via a Sierra Stats Dia. tool. Also checked by jumping the data link conn. Replaced the ECU with a new unit. same results. replaced the Crank & cam sensors. Same results. I intersected the F/P (blk/white) with a test conn. (male/female).(The VST is buried behind the intake) I can put a jumper to the motor block to the blk/white (separated from from the ECU) & the engine will run & maintain 40 psi F/P. A volt meter shows varying dc volts.(from the ECU) Some times 13.5 down to 4v. Strange that while the motor is off or running, the Sierra Stat showed the fuel pump was turned off. I pulled the (2) crank,(1) cam,& heat sensors 1 at a time. they would set a alarm & I could reset the individual alarms via the Sierra Stat.
Any suggestions as I am stumped!!
Iceman
Any suggestions as I am stumped!!
Iceman