Someone has asked me what may cause a 200 bar actual__with a 130 bar target__using the RS4 FPRV.
My suggestions were:
"What may be wrong is; the RS4 FPRV is stuck closed and doesn't allow fuel to return to the low pressure delivery line__its G247 fuel rail pressure sensor, sometimes even the G410 low pressure sensor on the HPFP, is reporting inaccurately__the N276 (pressure limiting valve on top of the HPFP) is not regulating rail pressure and may be stuck open__it may have wiring or power issues for any of the N276, G247 or G410__or injectors are not 100% open. And then in a more rare case, the ECU may be at fault."
What did I leave out?
I did include:
"Unfortunately, because the condition it has comes with a high number of possibilities, rather than replacing a long list of parts while keeping fingers crossed, you may consider taking it to a highly trained VW tech to diagnose it."
I lean toward the FPRV being at fault, because even if the injectors are stuck closed or if anyof the others may be causing the condition...the RS4 FPRV should still relieve the rail pressure when it reaches 140 to 150 bar.
My suggestions were:
"What may be wrong is; the RS4 FPRV is stuck closed and doesn't allow fuel to return to the low pressure delivery line__its G247 fuel rail pressure sensor, sometimes even the G410 low pressure sensor on the HPFP, is reporting inaccurately__the N276 (pressure limiting valve on top of the HPFP) is not regulating rail pressure and may be stuck open__it may have wiring or power issues for any of the N276, G247 or G410__or injectors are not 100% open. And then in a more rare case, the ECU may be at fault."
What did I leave out?
I did include:
"Unfortunately, because the condition it has comes with a high number of possibilities, rather than replacing a long list of parts while keeping fingers crossed, you may consider taking it to a highly trained VW tech to diagnose it."
I lean toward the FPRV being at fault, because even if the injectors are stuck closed or if anyof the others may be causing the condition...the RS4 FPRV should still relieve the rail pressure when it reaches 140 to 150 bar.