I hate my damn SFMU! I cant seem to lower the fuel pressure down to a respectable number.
From what I have seen from searches, and heard, I am supposed to take the vacuum hose off the the barb on the top to set the "static" pressure. SO I took the vacuum line off and turned the allen/screw thing in the top of the SFMU to where it is almost all the way out, BUT STILL NO PRESSURE DROP!!! WTF!!! I am running around 40psi at idle according to the gauge mounted to the test port on my fuel rail.
Am I doing something wrong?????? Please help, I am trying to go to the Shootout but my gas mileage sucks right now.
BTW I have the 2.22" ring and disk with the small ( silver ) spring. I also have 415cc injectors.
#54770, "RE: I hate my SFMU.....and I have questions" In response to Reply # 0
Leave the vac line hooked up when setting your pressure. With your injects, you should idle around 16-18 psi. You do need the longer, silver spring in it too, the one that factory ships with the SFMU, as this spring lets you idle at much lower fuel pressures. You may want to put in the next largest disk too, just to be safe..start out rich, then go from there..
13.5 @108 MPH-2.2 60ft(stupid FWD!) S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential fuel injection) My webpage: http://eclipsed4evr.home.comcast.net -1998 Mitsubishi Eclipse RS-T- "Toy" -1992 Plymouth Laser Turbo AWD(SOLD) -2000 Honda CR-V(daily)
#54774, "RE: I hate my SFMU.....and I have questions" In response to Reply # 1
you can do it his way ^^^ or redo what you did, but once you unplug the vacuum line to the super fmu block the vacuum going to the intake manifold with something ( to stick in ) and then adjust your static fuel pressure. also you still might have to use a different disk/ring if what i said does not get you low enough. good luck Michael 99gs (broken) Motor being built now HRC Stage 2 8-Injector Setup Fully Built by July 25,2003 hehe 2GNT Member #32
#54780, "RE: I hate my SFMU.....and I have questions" In response to Reply # 2
Does the smaller the disk and ring make for a richer or leaner overall condition. I thought the bigger injectors you have the smaller the ring and disk combo.
#54795, "RE: I hate my SFMU.....and I have questions" In response to Reply # 4
Don't worry bro your on the right path. I still don't have any extra fuel over stock, so I'm damn near 3000 miles on this motor and can't get on it. Try what they said about lowering the idle pressure first. (leave the Vac line hooked up and lower the pressure) then move to the static pressure, and so on. I have already realized there is no way for me to get to the shoot out, and it sucks. Keep at it bro your almost there.
I edited to the wiki!
Originally posted by DR1665 NOTE TO SELF: Go commando to wedding. Scar the Irishman for life.
#54800, "RE: I hate my SFMU.....and I have questions" In response to Reply # 5
So do you have the short/dark spring in, or the longer/silver spring in? you should use the long/ silver one to lower pressure. www.TeamKLR.com 1997 Silver RS Wiseco 8.8:1 Pistons(back to low compression!) Eagle Rods T3/T4 Turbo Custom FMIC Greddy Exhaust 440's Most current 1/8th mile time: 8.3@90mph 2.015 60'(Nitto Drag radials, i suck)
#54847, "RE: I hate my SFMU.....and I have questions" In response to Reply # 6
I have the long Silver spring in the SFMU right now with the 2.22" ring and disk combo. The ring and disk DO go UNDER the diaphragm right? Thats how I have it assembled.
I will try again tomorrow and see what I can come up with.
Kirby....thanks for the support and encouragement. I am almost at wits end with this car right now. One thing after another. Sucks thay you cant make it to the Shootout. I had a blast last year and have been looking forward to it since the day it ended.
#54851, "RE: I hate my SFMU.....and I have questions" In response to Reply # 7
Yeah, the disk, then ring around the disk, then the diaphram, then the spring retainer, then spring, then the other spring retainer, then the top lid of the SFMU. Be sure the SFMU bolts are not overtightend, or not loose, and be sure the diaphram is centerd and not kinked, ect..Tighen the bolts snugly, dont hammer em down..
13.5 @108 MPH-2.2 60ft(stupid FWD!) S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential fuel injection) My webpage: http://eclipsed4evr.home.comcast.net -1998 Mitsubishi Eclipse RS-T- "Toy" -1992 Plymouth Laser Turbo AWD(SOLD) -2000 Honda CR-V(daily)
#54857, "RE: I hate my SFMU.....and I have questions" In response to Reply # 8
hmmm...goodluck curing your problem. but i use the 2.72" disk to start out with. it should be the correct one for the size injectors you have. and you will most likely need to get the optional bleed valve to lower the boosted fuel pressure a bit. www.TeamKLR.com 1997 Silver RS Wiseco 8.8:1 Pistons(back to low compression!) Eagle Rods T3/T4 Turbo Custom FMIC Greddy Exhaust 440's Most current 1/8th mile time: 8.3@90mph 2.015 60'(Nitto Drag radials, i suck)