How far in is the screw on the RRFPR

[denglish318ti]

Hi fellas

Guess you must be bored of my random DASC threads now, but I hope this is the last one asking random questions. The screw on the top of my RRFPR has moved out of position and I need to put it back to standard. Here is a pic of it as it is now, I count 3, almost 4 threads.


I was wondering if any of you guys who have a standard DASC could count how many threads show on your RRFPR? I would be very grateful.

Cheers
Dylan

[macilona]

hello Dylan---pls send me an email at macilona@comcast.net to establish a dialogue----will try to help out. mac

[denglish318ti]

Mac wasn't able to help as he has NickG's software, lucky man! Any one else able to help me out? I think it needs to go a bit richer, I never see black smoke out the tail pipe, I am just worried I might put too much pressure on a fuel hose and it will come off!

Cheers
Dylan

[Danny318]

get a wideband o2 sensor

[lpcapital]

I just pulled mine out last night. I'll measure it with the caliper tonight...

[denglish318ti]

Originally Posted by Danny318

get a wideband o2 sensor

That would be nice, but I only paid £500 for the whole kit. To spend £130 on sorting out a wideband would be a bit over the top if I can just get it close enough by measuring.

Cheers Zeta, would be great if you could measure it with a caliper, better than counting the threads

[lpcapital]

Sorry for this... I totally forgot.

I'll do it tonight as I get home...

[lpcapital]

Ok, sorry it took me so long...

From the top of the screw to the surface of the RRFPR (not the nut, the actual RRFPR) it's exactly 7mm

[denglish318ti]

Originally Posted by lpcapital

Ok, sorry it took me so long...

From the top of the screw to the surface of the RRFPR (not the nut, the actual RRFPR) it's exactly 7mm

Cheers Zeta, I measured mine and it was 7mm too, but I had only adjusted that using my best guess. I bought a fuel pressure gauge and checked the pressure and to get it right it took the screw down to 4mm, which is a bit weird as I cant imagine there being too much variation between the units. Cheers for the help, it gave me the balls to turn it in some more!

Anyway, for anyone who needs help setting up there RRFPR (any make) you should do the following.
1) Install RRFPR after fuel rail. Flow should be Fuel pump --> Fuel rail --> RRFPR --> return line
2) Install a cheap £10 fuel pressure gauge which goes to 100psi BETWEEN the fuel rail and RRFPR. Remember to use teflon tape on the gauge joints (guess how I know!). Should now be Fuel pump --> Fuel rail --> Fuel pressure gauge --> RRFPR --> return line
3) Start car, check for leaks! Use some blunt pliers and crimp the line between the fuel pressure gauge and RRFPR. Check pressure reaches 100psi and then release. Dont hold it at that pressure long. This checks the fuel pump can reach the needed pressure.
4) The pressures we are looking for are about
40psi idle, 18InHg vacuum
50psi 0psi
75-90 psi at 8psi boost
Screw the top screw in to get the fuel pressure to increase. You can check the pressure at 0psi by removing the small hose that goes to the top of the RRFPR. Leave the RRFPR open to atmosphere, and plug the end that goes to the manifold up.
Only way to test at 8 psi is to drive it. I taped my gauge to my windscreen wiper so I could see it inside the car. DO NOT RUN THE GAUGE INSIDE THE CAR

Car now pulls a lot better, I am still only at 80 psi fuel pressure at 8psi boost, I might crank it up a bit more to be on the safe side, but its nice to have a car that works quite well. Now where can I buy a smaller pulley and a ECU with the NickG software on

[adrnln]

RRFPR goes AFTER the stock fuel pressure regulator. Depending on the year the stock FPR is on the fuel rail or under the driver's seat. Make sure you follow the D/A manual because the later model M44's need to have the fuel line take a "U" turn after the 3/2way valve to the AFPR (RRFPR) and then to the fuel tank.

Also, 75-90psi seems a bit high for 8psi. I think it should be closer to 68psi.

Sheridan

[denglish318ti]

Real OEM would have you believe that all M44 fuel pressure regulators are in the same place (on the fuel rail). This is a 94 car:
http://www.realoem.com/bmw/showparts...16&hg=13&fg=15
And this is a 99 car:
http://www.realoem.com/bmw/showparts...16&hg=13&fg=15
I have done a lot of research into the correct fuel pressure and it seems most people have the best results at about 85psi. Mine was at about 70psi, and as soon as I turned it up to 80psi the car was a totally different animal, so much better.
Just my finidings though