Adjustable Fuel Pressure Regulator

[maston]

I have just discovered that my 390 has an adjustable fuel pressure regulator which can be adjusted via an allen key.
Just out of interest which direction do you turn it to increase and decrease the fuel pressure ?
Also is it best to leave it as is or can I have a little fettle with it ?

Many Thanks

Ian

[Jack Valiant]

Hi Ian

I did not see a Rising Rate reg on your car but I may be wrong! Anyway never fiddle with fuel pressure unless you have a good in line gauge (Like the one on my car if you recall) If you over cook it you can cause the injectors to leak, wash out the bores with fuel and a big bang! if I were you I would get all the rubber pipe work in the fuel rail and injectors replaced as it was leaking when I last saw it and also check the main lines from the pump forward, then if needs be, get a gauge and see what is going on with the fuel pressure.

Cheers

Chris

[tweety]

My 390 has one too and a gauge, it runs at approx 38psi I think but was told it will need turning down to 30 for the MOT which is imminent, does this sound right?

Cheers, Al.

[maston]

Thanks Chaps for your replies.
Chris, You may be right ?
How are you anyway mate ?

I took it to a tuning garage yesterday and was told that there is little that can be done to tune it but he showed me on the regulator where the allen key turn screw is ???
Cheers Al for your reply too mate.

[Wedg1e]

I'd expect it to be clockwise to increase fuel pressure (you're usually altering the pre-load of a spring). My car has the standard Bosch adjustable FPR and as little as half a turn either way takes it from spot-on to undriveable. About 1/8th of a turn increase makes the car take off like a mis-identified lion at high revs but it runs like a washing machine with a brick in it at the bottom end.
So play if you like, but remember EXACTLY where you started

[maston]

Thanks Ian, might have a little look tonight

Regards

Ian

[grahamw48]

A rolling road will set it up properly for you for about £30 (1 hour)...as I had done with my adjustable reg. They will also point out all the other things that are fked.

A lot cheaper than damaging your engine.