yes i am running a walbro...
and this is weird coz at some point while i was messing around with the FPR trying to adjust it...my walbro went nutz and starting whining extremely loud on an off..on and off..it didnt stop whining until i turned off the ignition and started the car back up......

can you clarify something though?.... what do you mean my return line is plugged?? do you mean its blocked and not returning anything to the tank?

also..how could i test for a faulty regulator..is the only way to swap it out for another?

thanks

 

If the return line is pinched or blocked it will cause high fuel psi readings. The return line is the line on the bottom of the regulator. Make sure there are no kinks or anything jammed up against the line.

As for checking the reg, Only way I can think of is run the car turn it off and make sure the preasure dosen't go below 20psi after 5 min. If it does or is at 0 after 5 min then either a line is leaking, an injector is leaking, or the reg is not doing its job.
Good luck man

 

just to clarify your install, the fuel supply line enters the rail from the driver side, exits the rail on the passenger side and goes to the fpr. The fpr should have 3 ports. Two large ports on the side, and one smaller port on the bottom of the fpr. The two large ports on the side are inlets, one should come from the rail and the other should be plugged. The smaller port on the bottom of the regulator ties into the fuel return line that goes back to the tank. Hopefully this is how yours is installed, unless SX has changed their design.

 

yes double ugly...this is exactly how mine is installed....

 

i already performed that check...my fuel pressure doesnt drop below 20 psi for atleast 18~20 mins i would say

 

here is a video of what is happening..i hope this helps

http://youtube.com/watch?v=oXl2jhbttTk

 

notice how it turned at exactly 1:00min of the clip because i didnt try to balance the throttle

 

I know it is a different FPR but follow these directions

http://www.amsperformance.com/instru...structions.pdf

You might not have a rising 1:1 FPR.

 

i also just checked the return line both from the fuel rail to the FPR...and from the FPR back to the tank :S

 

those are the instructions i used to install it me and my mechanic...

and my SX FPR looks exactly like that too

 

What FPR model did you get and who did you get it from?

 

my bet is your regulator is messed up or there is a restriction in the fuel return. The bounce up to 6 bar (plus) is the fuel pump switching from low speed to high speed. Yes, the evo has a two speed pump based on load, and when you rev like you are doing in the video, the pump is switching to high speed mode, and the fuel pressure regulator or return line just can't flow the extra fuel to control pressure.

 

It seems like the relief spring is binding inside. The way these work is there is a spring inside that seats a ball. As you tighten down on the spring you increase the fuel pressure. When the pressure over comes the spring tension it relieves the excess fuel to the return line.

 

i will have all lines removed tommorow and inspected to see for any ristrictions..

doubleugly...one more last question...when you say the return line...are you refering to the return from the fuel rail to the regulator or the return from the regulator back to the gas tank?

thanks and your help is very much apprecited..

 

I would hook up a mechanical gauge and read the psi reading off that. Its possible the electronice sender or gauge is messed up. Mechanical will always tell the truth.