Okay I called up Vortech and asked them bout my malfunctioning FMU. They wanted $55 to repair it...f dat. I asked them how the FMU worked and he said a piston insdie the FMU restricts the flow of fuel. When I openned up the FMU there was no piston to be found. Now the question is for those who have taken apart the Vortech FMU: Is there supposed to be a little piston insdie?? OR better yet if someone could do me a HUGE favor and teardown the FMU and tell me what they find. Help me out cuz i don't wanna pay $55 for a little part that i can put in myself. Thanks

Alvin

96 RST

http://www.kaptainmyke.com/tir/gallery/SemperBoost
Star Stage I turbo kit /Starion I/C w/ 2" chrome piping / GReddy Type-S BOV / Missing Link / Custom APEXi- GReddy 2.5" exhaust / Nology wires / Dual Gaugepod pillar mount / APEXi EL mech boost gauge / Autometer A/F gauge / Southland Dual Friction clutch / B&M short shifter / Energy Suspension shifter bushings / 16" GSX Rims / Front/ Rear camberkits / Eibach Prokits / Tokico Blues/ Front Upper, Rear Upper/Lower strut bars / Rear GST sway bar
X-drilled rotors / Axxis pads / Stock GS/GST sideskirts /Color-matched center taillight/ door handles/ sideviews
Cleared Headlight turns/PIAA bulbs

How did you determine that your fmu was bad?

I have fuel cut at 3/4 throttle and at WOT OR anytime i try to go into boost. It'll start of cycling then go to rich around 3.5k with the gas mashed mashed then at 4k the needle just almost comes to a dead stop..it slows down and my car just loses power and the A/F gauge swings Lean. I haven't had a chance to measure my fuel psi yet but I'm sure it's pulling timming cuz of the fuel

Alvin

96 RST
http://www.kaptainmyke.com/tir/gallery/SemperBoost
Star Stage I turbo kit /Starion I/C w/ 2" chrome piping / GReddy Type-S BOV / Missing Link / Custom APEXi- GReddy 2.5" exhaust / Nology wires / Dual Gaugepod pillar mount / APEXi EL mech boost gauge / Autometer A/F gauge / Southland Dual Friction clutch / B&M short shifter / Energy Suspension shifter bushings / 16" GSX Rims / Front/ Rear camberkits / Eibach Prokits / Tokico Blues/ Front Upper, Rear Upper/Lower strut bars / Rear GST sway bar
X-drilled rotors / Axxis pads / Stock GS/GST sideskirts /Color-matched center taillight/ door handles/ sideviews
Cleared Headlight turns/PIAA bulbs

alvin,
the upper half of the fmu is just a vacuum chamber which consists of a rubber diaphram and a disk and i think some type of spring. the lower half of the fmu, which they say you should not take apart, houses the piston and valve. are you using any rings with the disk in your fmu?
you are still using the standard fmu right? if there is any tear in the blue rubber diaphram the unit will not work. it will leak boost and then not regulate the fuel pressure. I have a spare rubber diaphram that you can have if you want it if yours is messed up.
lates
james

I think I'm missing the piston thing. When I opened the vaccumm side of it..it's just the blue diaphram and the 12:1 (no ring cuz 12:1 doesn't use it) Inside the fuel chamber all there is is another blue diaphram, o ring and a thin metal disk. I think I missing something. Is there something that goes between the vaccumm chamber and the fuel chamber..piston? If upi check on this site:http://www.stangnet.com/tech/injectors/fmu.html. On the second picture there is a metal circular thing that is on the fuel chamber surrounded by the 4 bolts. What is that..i think i maybe missing it
Can someone post pics or something.. James the fuel diaphram is a little torn near the screws. Thanks for the replies guys

Alvin

96 RST

http://www.kaptainmyke.com/tir/gallery/SemperBoost
Star Stage I turbo kit /Starion I/C w/ 2" chrome piping / GReddy Type-S BOV / Missing Link / Custom APEXi- GReddy 2.5" exhaust / Nology wires / Dual Gaugepod pillar mount / APEXi EL mech boost gauge / Autometer A/F gauge / Southland Dual Friction clutch / B&M short shifter / Energy Suspension shifter bushings / 16" GSX Rims / Front/ Rear camberkits / Eibach Prokits / Tokico Blues/ Front Upper, Rear Upper/Lower strut bars / Rear GST sway bar
X-drilled rotors / Axxis pads / Stock GS/GST sideskirts /Color-matched center taillight/ door handles/ sideviews
Cleared Headlight turns/PIAA bulbs

Alvin,
That silver thing is the piston. if you don't have that the unit will not regulate fuel pressure. it needs to go in there because that is what the disk presses on to restrict the flow of fuel.
lates
james

I think when my mechanic took it out to adjust something he forgot to replace it...cuz I don't have it!..I gues I'll run with no FMU for awhile till it gets repaired. I think I'll be able to run 2lbs without any problem..haha..thanks james

Alvin

96 RST


http://www.kaptainmyke.com/tir/gallery/SemperBoost
Star Stage I turbo kit /Starion I/C w/ 2" chrome piping / GReddy Type-S BOV / Missing Link / Custom APEXi- GReddy 2.5" exhaust / Nology wires / Dual Gaugepod pillar mount / APEXi EL mech boost gauge / Autometer A/F gauge / Southland Dual Friction clutch / B&M short shifter / Energy Suspension shifter bushings / 16" GSX Rims / Front/ Rear camberkits / Eibach Prokits / Tokico Blues/ Front Upper, Rear Upper/Lower strut bars / Rear GST sway bar
X-drilled rotors / Axxis pads / Stock GS/GST sideskirts /Color-matched center taillight/ door handles/ sideviews
Cleared Headlight turns/PIAA bulbs

hey alvin
check ebay,
i think you can get a fmu cheap on there.
i've seen some go for like 30 or 40 dollars
lates
james

Well I tried looking on Ebay and the cheapest I found one was $90..I thik I'll just send mine in and hopefully the turn around won't be long. I wanna start boosting asap

Alvin
96 RST


http://www.kaptainmyke.com/tir/gallery/SemperBoost
Star Stage I turbo kit /Starion I/C w/ 2" chrome piping / GReddy Type-S BOV / Missing Link / Custom APEXi- GReddy 2.5" exhaust / Nology wires / Dual Gaugepod pillar mount / APEXi EL mech boost gauge / Autometer A/F gauge / Southland Dual Friction clutch / B&M short shifter / Energy Suspension shifter bushings / 16" GSX Rims / Front/ Rear camberkits / Eibach Prokits / Tokico Blues/ Front Upper, Rear Upper/Lower strut bars / Rear GST sway bar
X-drilled rotors / Axxis pads / Stock GS/GST sideskirts /Color-matched center taillight/ door handles/ sideviews
Cleared Headlight turns/PIAA bulbs