C4SxM5

During my UPGRADE to a 10psi pulley I noticed my B&M Fuel Gauge not working any longer (not sure if it was working right before or not, but for sure worked originally). Wondering if the gauge has gone bad or did I forget to hook something back up?

Also, what am I'm suppose to do with the FMU now since the EMS controls the fuel?

Legend for picture below:
Red arrows show what was removed and reattached.
Blue arrow shows that a screw was stuck in the tubing to seal it.

Scorpion

Remove the FMU if you are running an EMS. I have a question for you though...where is your fuel pressure regulator?

C4SxM5

I'm not sure, isn't the FMU and the FPR the same thing?
This is it right?

Asura

Hey Tan
FMU (Vortech) is the ESM (Comptech) on the ECU harness if still there.

red arrow 1st pic is PCV vacuum - no effect on fuel pressure.
blue arrow 1st pic is the vacuum hose that normally goes to the Comptech RR FPR.

Yes, the red UFO in the last pic is the Comptech FPR.

Scorpion

Not really. A FMU adds extra fuel pressure based on boost pressure, it's a poor mans way of tuning. A FPR only increases fuel pressure by the amont off boost it sees. maybe this will help

10psi of boost on a 47psi fuel system.

With an FPR you'll run 57psi of fuel under full boost.
With an FMU you will be running well over 57psi of fuel, how much depends on the ratio the FMU is rated for. The ones that come with the Vortech kit are 8:1. I'm not sure if that's 8 psi extra, or 8x, but I'm assuming it's 8psi extra. So at full boost you'd see 65psi of fuel.

Makes sence?

C4SxM5

THANKS I was actually waiting for you to come on AIM
I already removed the ESM while installing the EMS, so that's cool!

SO the vacuum hose with the screw in it is fine or do I need to do something else?
Also, should I remove the FPR or leave it alone? Any ideas why my gauge isn't working?

THanks again

Scorpion

No, the FMU is a blue version of what is in that pic. The only differance in the Vortech FMU and the Comptech FMU is that the Comptech is adjustable. Both kits come with a ESM (Electronic signal modifier) which is how they change the signal form the map sensor so the ECU doesn't throw a CEL under boost.

Scorpion

I suggest you either find the stock FPR and put it back on, use the capped vac line for it, or buy a adjustable one. As far as I know, you can not make the comptech FMU a 1:1 unit.

Asura

Well...

1)Is the gauge liquid filled? Is it broken?
2)Looks like you have a banjo under the gauge going to the FPR so it should be getting fuel.
3) You need an FPR so don't remove it. I an guessing the screw in the hose converts the rising rate fpr to a static rate one...NOT SURE on this though. I went with a static rate AEM FPR.

Is your car running ok? Non-liquid filled gauges will break from engine vibrations...I would start with checking the gauge.

Scorpion

[QUOTE=Asura,Jan 5 2006, 02:53 AM] I an guessing the screw in the hose converts the rising rate fpr to a static rate one...NOT SURE on this though.