fuel pressure regulator !!

[al 350i]

can anyone help me, i've got a 400se and the fuel is coming upto the fuel pressure regulator but doesn't seem to be able to get past and into the fuel rail, i'm pretty sure its a sealed unit so probably can't do much with it. my question is does anyone know where is the best place to get a replacement and is it best to replace it with an after market uprated one?

[peaktorque]

al 350i said:

can anyone help me, i've got a 400se and the fuel is coming upto the fuel pressure regulator but doesn't seem to be able to get past and into the fuel rail, i'm pretty sure its a sealed unit so probably can't do much with it. my question is does anyone know where is the best place to get a replacement and is it best to replace it with an after market uprated one?

The regulator is fitted on the return side of the rail.

Is your fuel pump running?

[al 350i]

aahh!! i think i might have made a bit of a mistake then when i put the inlet manifold back on, the fuel pump is running and will pump the fuel up the line and comes out of the pipe that connects direct to the regulator. should it be connect to the other pipe to the right of the regulator????

[peaktorque]

The fuel pump should pump straight into the rail and the regulators job is to maintain the desired pressure available to the injectors and release any surplus back to the tank.

[al 350i]

makes perfect sense now!!

i was wondering how it would manage to maintain the pressure. it was a nice day today and was rushing things so i could jump in the cerbera and take it down to beastead green for "cars on the green". that'll teach me not to take photos.

many thanks, will swap the pipes over tomorrow, really want to get out there tonight as it hasn't run for 8 years but don't think the neighbours would be too pleased.

[ed_crouch]

Yeh the reg is a spill valve, it allows fuel to flow back to the tank return should the upstream pressure be too high. If you've plumbed the reg into the upstream side of the rail, all the injectors will see is spill flow at atmospheric pressure. Admittedly the spill flow will be the full fuel pump flow, but the reg will dump all the pressure, and you'll be damn lucky if the car runs at all.

[ed_crouch]

don't think the neighbours would be too pleased


Pah, screw 'em!

[al 350i]

its ok i'll fire up the cerbera (de-catted), they'll never hear the wedge