LOW FUEL PRESSURE - out of ideas! HELP

[JamietoddUK]

Hi all,

New member of this forum, have been an MPS OC member for a couple years in the UK now and have a fully bolted BNR4 mk1.

So in September last year I got an issue with low fuel pressure, sitting at 40-60PSI on idle and pushing to 100PSI when trying to drive - the car is undrivable at the moment, zero power and very stutter, however it will sit and idle all day with no hiccups at 50 ish psi. I also had a code P0091 which is "fuel pressure regulator control circuit low voltage", but somehow this has now disappeared but the symptoms have not. So far I have tried -

Swapping whole HPFP with another club member
Relief valve (twice just on the off chance that I bought a 2nd hand one that was also ruined)
fuel pressure sensor
In-tank fuel pump which contains the regulator its self

Any other ideas? it has been off the road since September and im forgetting what its like to drive!

 

[Ssinstaller]

Damaged wiring between the spill valve solenoid and the Ecm, possible bad ecm. You've checked everything mechanical, so the issue has to be electrical.

 

[Brado]

What ended up being the issue?

 

[Francisco]

Hey Jamie, I know it's been years from this Forum, but I was wondering what did you do to fix it, if you remember? I've done everything that you've done as well.

 

[Awafrican]

Hey Jamie, I know it's been years from this Forum, but I was wondering what did you do to fix it, if you remember? I've done everything that you've done as well.

OP hasn't logged in since he posted this question I doubt we'll hear from him. I recommend making your own thread in the troubleshooting section using the pinned thread as a template