paxton fuel pressure

Discussion in 'Performance Mods' started by areuv, May 28, 2007.

  1. areuv

    areuv Full Access Member

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    my 05 QC has a paxton, big heat exchanger,crank evac setup, and a built trans, last couple of days the truck has felt down on power, was driving around trying to check boost when I noticed my fuel pressure gauge bouncing around, at idle it's 60psi, but when I get on the gauge bounces up, half throttle and it went to 80psi and then I floored it and the needle was pegged on the gauge, I never noticed this before, I didn't recall seeing my fuel pressure gauge move around like this, also I'm getting some flames out the exhaust, can any paxton guys tell me what their fuel pressure does under wot, thanks for the help.
    Asher
     
  2. jrgnd

    jrgnd Full Access Member

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    I notice the same thing...With the heat, I think we are dumping a huge amounts of fuel...Contact Boomer and ask him what he suggest...I removed one of the two buttons in the FMU. It made a huge difference so be careful.....In my truck it was going in the 9s at WOT and now it only goes to 10.3 and leans to 11.6 on the high end...
     
  3. AWDisuzu

    AWDisuzu Full Access Member

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    sounds like you're running rich cowboy! it's possible your fmu is flakin out. however, it's normal (expected) behavior for the fuel pressure to jump up in relation to manifold pressure. so under full throttle it should be pegged.

    but still, i think you're running toooo rich if you see flames! you also may have a fouled sparkplug or 2 which would explain the flames and the power decrease.

    good luck!
     
  4. JTS VENOM PERFORMANCE

    JTS VENOM PERFORMANCE New Member Preferred Vendor

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    I think ya'll should chunk the fmu bandaid, and get a real fuel system:D
     
  5. Ram From Hell

    Ram From Hell Full Access Member

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    Yikes!

    Sounds like the FMU has gone bad. You might try disconnecting the vac/boost line (don't get into boost, and watch air/fuel while driving) and see if your fuel pressure remains more consistent.

    Stinker's right though. The Paxton system's a bandaid. For me it's going to be like a bandaid on a mortal wound!:D Time to talk to UGR. They will set you up for whatever power level you're running at.
     
  6. JTS VENOM PERFORMANCE

    JTS VENOM PERFORMANCE New Member Preferred Vendor

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    actually its pretty simple, well kinda:D

    I may be a tad different than most(huh magine that:D ) but I like one fuel pump, one set of lines, and one regulator, kinda old school.

    but that way I never have to worry about one of the pumps going out, and having a lean condition, or wiring up a hobb switch.

    But I personally think we need to get SLH motorsports or Justin one to fab us up some fuel rails, nothing expensive or elaborate, jsut where they will work with an fittings.

    then all ya got is to run the fuel lines to the pressure regulator , pump and tank.

    only problem is connecting to the tank, in your own way.

    now if you put a fuel pump on the frame rail, it will be noisy, i have gotten used to mine.

    I do know UGR is getting there machinist to fab up a new tank insert to mount pumps in the tank with correct fittings, dont knwo what they will cost, but looked nice, this would give no noise, keep the pumps cool aslo..

    now the prob with my pump is it gets hot, eventually it WILL go out, but at the same time I want have to drop the tank to replace it:D