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Thread: Injector problems

  1. #1
    Join Date
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    My friend has a 68 chevy truck with a 99 LS1 in it. Have fuel all the way to the rail and everything works but the injectors. You can keep the truck running with some starter fluid but you know how that goes, just for a few seconds. We too k the PCM out of the Porsche 914 and put it in the truck just to see if that was the problem but still no luck. What would keep the injectors from firing that you guys can think of? It has the fuel filter with return line and like I said 60 psi at the rail with plenty of spark to the plugs.


    97 GMC, 2002 LS6.

    1991 GMC Syclone #1428

  2. #2
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    I could be wrong but isnt there a seperate fuse for the injectors, I thought I remembered seeing something one time for them in the fuse box but I could be wrong.

    Chris
    2009 Silverado, HPTuners, all stock.

  3. #3
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    <div class='quotetop'>QUOTE(chrisj6 &#064; Sep 26 2006, 07&#58;09 AM) [snapback]66633[/snapback]</div>
    I could be wrong but isnt there a seperate fuse for the injectors, I thought I remembered seeing something one time for them in the fuse box but I could be wrong.

    Chris
    [/b]
    There are two fuses one for each bank of injectors. The injectors should have power + when the key is on. The PCM pulses the ground. You can use a test light (they sell noid lights at the autoparts) to check for injector pulse.
    2006 Superior Blue Trailblazer SS AWD, Stock as a rock

    Sold: 2002 GMC Sportside Denali front end with a 2002 LS1, FLT level 5, Yank 2600, Trick Turbo, T76, Nelson intercooler, 60LB injectors, Warbro fuel pump, Eaton locker, Magnaflow, 3.42, Nelson Performance Tuning (speed density).

    Sold: 1981 GMC LB RC 1500 2002 4.8L 4L60E 12 bolt 3.73 Richmond Lock Right AC PS Nelson Performance tuning

  4. #4
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    Sorry I didn&#39;t put this in the post but yes, fuses are good and there is voltage to the injectors with the key on just no fuel.

    BTW, I&#39;m just asking questions I haven&#39;t personally looked at it myself but the guy whol is looking is an instrument tech so he has excellent electrical experience.


    97 GMC, 2002 LS6.

    1991 GMC Syclone #1428

  5. #5
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    Is this a first start of a new swap? Has the engine been sitting for a while? If so, and you&#39;ve verfied fuel pressure and voltage to the injectors, the problem may be as simple as stuck injectors.... happens all the time on dormant engines. A quick fix is to remove the injector connectors and apply 12V directly to the injector (12V to one pin, ground the other) remove and reapply the power (or ground) repeatedly until you hear an audible click from the injector. Replace the connector and move on to the next one. Both swaps I have completed had this issue (junkyard and Ebay engines).

    1965 C-10 shortbed stepside, 2003 5.3/4L60E conversion. Power steering, tilt wheel, power front disc brakes, 3.73 one wheel peel, 2.5/4 inch drop, relocated fuel tank and battery, 2002 Silverado buckets and console. Swap Pics
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  6. #6
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    Also, check the fuel rails for trash build up.
    2000 Chevrolet Silverado, 4.8L, K&N polished intake, 4.10 gears, 20x9 KMC SS on front, 22x10 on rear, Dual style pillar gauges, steel cowl hood, 2" rear drop shackles, true duals w/IMCO extreme mufflers w/dumps at rear end, SLP headers. Cam and nelson tune soon to come!!!!!

  7. #7
    Join Date
    Jun 2006
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    problem may be as simple as stuck injectors.... happens all the time on dormant engines.[/b]
    This happend to me exactly.....had my dad&#39;s linconl towncar sited for more than 2 years cause he did not want to rebuild the engine.

    about six month I talk him to buy the parts, and I rebuild it. Everything in place the car did not start....check everything until and old Electrician took an injector out and put to it 12v direc from a mack truck batery, sound klick, and we did to all, the car start perfect. I was thinking after that to send the injector to clean, but never felt the need for that, the car runs good and smoth.

    The Car been old, a 93 Cartier TonwCar, had a 4.6L with 2 cams overhead and FI that came after in the 99 trucks.
    Need a Freakin&#39; Roll Cage, and a Death Insurance

  8. #8
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    May 2004
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    I&#39;ll ask him guys. Supposedly this is a new set of 42lb injectors but you never know what they have when they&#39;re telling you over the phone. I have a new set of 28lb&#39;ers I&#39;ll take him to try if they aren&#39;t new. I&#39;ll keep you guys posted. Thanks


    97 GMC, 2002 LS6.

    1991 GMC Syclone #1428

  9. #9
    Join Date
    Nov 2003
    Location
    Denton Texas
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    take them all out of the fuel rail, turn them upside down and rap the top end of the injector sharply on a wooden block. That will unstick them.
    See my truck data in the "My Garage" section here... http://www.ls1truck.com/forums/my-ga...tml#post191709

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