How do you adjust your FPR?

[newdude1]

I just bought a new Tomei fpr and I know clockwise is more pressure and counter is less but do you remove the vacuum like to adjust it?

[PapaSmurf2k3]

no, you don't have to, but you can.

Removing the vacuum line will just increase your fuel pressure a little bit. Usually FPR's diaphrams increase fuel pressure 1psi for every 1psi of positive manifold pressure... so you run a little more pressure at WOT than you do at idle.

[newdude1]

thanks. So I went to start the car and I have no fuel pressure now. Maybe I have my lines backwards. I have this onehttp://www.frsport.com/Tomei-1....html

I have the line coming from the filter into the bottom of the fpr then the line coming out the side to a inline gauge, then to the motor. Is that correct?

[PapaSmurf2k3]

Not at all.

The line from the filter should go directly to your fuel rail, and the line coming from the fuel rail should go through the gage, then that line should go to the side of the FPR, and the bottom of the FPR goes to your return line.

The FPR goes AFTER the fuel rail. Being this is a returning system, it acts differently than say, a pneumatic air line, where your regulator goes before the device you are trying to regulate.

[newdude1]

ok.... Im lost then heres what I have-----fuel filter----fpr---inline gauge---nismo adapter which is conected to the oem fuel rail then too 740cc injectors.

Can you lay out a little diagram like that so I can see what exactly you mean?

[biggie]

Probably the way it will work for you, if I can think correctly.

Fuel Filter to gauge to Fuel Rail to Nismo adpt to FPR to return line

[newdude1]

So I have been looking around and this is what I came up with so far. If someone can tell me if its right or not and what it should be would be great.---fuel filter----nismo adaptor----fuel rail----(return line)---- gauge-----fpr---return to the tank.

[newdude1]

Also how does it work being located after the rail? Since the stock one is before the fuel rail. Can someone explain that too for me?

[biggie]

Also how does it work being located after the rail? Since the stock one is before the fuel rail. Can someone explain that too for me?

Stock one is not before the rail. Gas runs from tank to fuel filter to rail, then to fpr and then back to tank. Should be the same now with your aftermarket fpr.

[newdude1]

Oooo. k Ya thats back wards on mine. Thank you Im gonna go fix that and see what happens.

[newdude1]

K now I got the lines right and I have fuel pressure. But its leaking at the threads on the fpr. I used teflon tape. Was I suppose to use something else?

[newdude1]

So do I set the fuel pressure to 43 with the vac line disconnect and when I connect it, it should be at 38?

[PapaSmurf2k3]

So do I set the fuel pressure to 43 with the vac line disconnect and when I connect it, it should be at 38?

Yes, roughly.

K now I got the lines right and I have fuel pressure. But its leaking at the threads on the fpr. I used teflon tape. Was I suppose to use something else?

Yeah I dunno, you must have done something wrong. I don't think there is any tape on mine at all.



So fuel comes up from the bottom-right. It goes to the filter. The filter then has a hose that connects to the middle-right side of the fuel rail. From there, it goes out the left hand side (near the firewall) via the NISMO fpr adaptor. After that, it goes to your regulator, and from your regulator it goes to the return line back to the tank.

I suppose you could really put the gauge wherever you want, as anything in front of the FPR will have the same pressure. Just make sure you don't put it on the return line after the FPR.