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Thread: New Injectors!

  1. #1

    Default New Injectors!

    PART 1:

    Alright guys I replaced my poppet fuel injectors with the new updated MFI injectors (SCPI to MFI) on my truck. Started about noon and finished around 5.
    here some of the process...

    after removing the air intake...

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    most all of the connections out of the way

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    upper intake off, i had to remove the thermostat because it blocked the upper intake from coming out :/
    look at all the black crap built up in there.
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    dirty old nasty injectors..

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    heres a quick comparison

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    this photo was after my careful cleaning, didnt wanna clean too much and worry about getting the cleaner i used into the port holes and messing something up, so i used it wisely...

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    The new injectors in place

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    End result???
    I can definitely feel a smoother idle, it seems to run very smooth now. Seems like a might have picked up a little peppiness in my engine too, although i wasnt expecting too...
    however this did NOT fix my cold start misfires :/

    i think i may have found the culprit...

    PART 2:

    does anyone think that THIS crack can cause possible condensation in the cap or anything to cause misfires???

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    also look at this, no bolt in there holding the fuel lines to the block, which actually saved me some time.
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    Looks like the shop who replaced my lower intake gasket only about 2 months ago overtightened my cap and cracked it and my distributor, AND they forgot to put a bolt back into place for my fuel lines!
    I will be going back to them later this week to show them the pictures and see if they believe what i am saying. Im pretty set now that they are the reason my truck started misfiring again, gahhh this is why i do all my own work!
    I make sure i have everything put back in right!

    other than that rant, I can definitely feel a smoother truck and it also seems to start up quicker too, which it already started pretty quick anyway, hopefully ill see something in the MPG dept as well
    2000 Chevrolet Silverado

    4.3L V6, 4L60E, 2WD, Single Cab
    Airaid CAI
    Poweraid TB Spacer
    Flowmaster 10-series exhaust (dumped)
    Edge CS insight monitor
    4.10 gears
    Limited-slip differential
    LS-1 Dual Electric fans
    Corvette tranny servo swap

    Head Unit: Alpine
    Speakers: Alpine SPR-60C 6.5" component set, 4X6 Infinity Kappas
    Subs: 2-12" Kicker CVT's
    Amps: Alpine-M1000 (subs), Alpine MRX-F65 (Speakers)

    305/70R16 NITTO Terra Grapplers
    16" PROCOMP 7089's
    2" leveling kit
    3" Fabtech Spindle Lift Kit
    Front/Rear-Bilstein 5100 shocks

    35W HID Low Beams
    RECON LED smoked roof cab lights
    HELLA LED taillights and 3rd brakelight
    HELLA FF-75 Aux. Reverse Lamps
    RIGID dually D2, flush mount, wide beam
    Hawk HPS Brake pads
    Russell braided steel brake lines
    Powerstop-red powdercoated brake calipers
    Powerslot Cryo brake rotors
    EGR in-channel window visors

  2. #2


    So what the actual difference between CSFI and MFI?

    1996 Chevy Tahoe LT 5.7L V8 4X4 205,000+ miles. Built proudly at Janesville Assembly in Janesville, Wisconsin
    Basic mods: Lights all over, bunch of electrical work, and a couple cooling mods.

    Check out my other mods in My Garage:

  3. #3


    the only difference i know of is from a reliability standpoint, the poppet valves are notorious for clogging up and the MFI upgrade supposedly is not as susceptible to that

  4. #4


    Makes sense but which is more efficient and more technologically advanced. All new Chevy trucks use SFIso which is the better.

  5. #5


    the updated MFI injectors are more efficient and more technologically advanced, i dont know about the difference between them and the SFI your speaking of, but definitely more so than the poppet valves

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