1999 454 Vortec misfire issues

Discussion in '96+ Vortec Performance + Computer Swaps' started by Saab84mw, Nov 4, 2019.

  1. Saab84mw

    Saab84mw Newbie

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    I just installed the MSD cap and rotor less than a week ago.
    The only issue I had was the screw that holds the cap on split the mounting hole on the distributor so I had to run a bolt all the way through the cap and distributor with a nut on just one side.
     
  2. 4x4burbs

    4x4burbs Newbie

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    I'm not saying it will fix it, but since you haven't replaced the ignition coil while this has been happening, it definitely can't hurt. I've been using a Screamin' Demon coil from performancedistributors.com for almost 10 years (along with the corresponding Dyna-module) and haven't had a single ignition issue. As far as recommended distributors, I put a Carquest special in (aluminum housing) almost three years ago now and have had no issues. I'm also using Taylor wires.

    https://shop.advanceautoparts.com/p...8-P?navigationPath=L1*14923|L2*15034|L3*16062

    I hope this helps you.
     
  3. Saab84mw

    Saab84mw Newbie

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    I replaced the stock coil with a MSD coil at the same time as the MSD cap and rotor.
    I think I will try the carquest distributor and check the connections also change the ignition module.
     
  4. Saab84mw

    Saab84mw Newbie

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    Well now I have a new issue!

    I was towing my travel trailer from Jacksonville up to Jekyll Island when I got into Georgia I was going over a overpass when the transmission downshifted the RPMs went to 3000 it downshifted again to 4000 and popped about three times like it was backfiring noticed I started losing oil pressure down to about 10 psi figured I better get off the expressway halfway down the offramp the oil pressure dropped to zero and the engine cut off after the truck cooled down tried to turn the motor over would barely turn over if any at all. 217000 miles on this motor

    Time for a long block any suggestions go with a straight up stock long block or maybe have it rebuilt and do a cam upgrade want to go a little more overstock but not too much want a reliable Tow vehicle.
     
  5. Mangonesailor

    Mangonesailor I'm Awesome

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    Well now that you've roasted the motor, let us know if you find anything when you pull the dizzy cap.
     
  6. Saab84mw

    Saab84mw Newbie

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    Yes Sir I will
     
  7. L29Sub

    L29Sub I'm Awesome

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    Pull the distributor and check the gear. You might find that the gear is not correct for the roller cam and is destroyed.
    Vortecs require "melonized" or pickled gears. The steel gears fit, but don't last. As they wear, timing gets out and they miss when idling and under heavy load. This can be observed in ign timing dancing around prior to failure.
    A grossly failed distributor would cause what you describe. Distributor drives the oil pump. And, a failed oil pump will destroy the distributor....and every thing else. Dist failure is common enough, oil pump failure is rare. If the engine still turns, might be salvageable.

    Sent from my SM-G965U using Tapatalk
     
  8. Saab84mw

    Saab84mw Newbie

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    Thanks for the information didn’t know the distributor was driving the old pump.

    The distributor was replaced about 4 to 5 years ago still doesn’t mean it couldn’t have failed.

    I will pull it to see what condition the distributor and is in and also check to see if the engine still turns over.
     
  9. L29Sub

    L29Sub I'm Awesome

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    Actually, you could pull the cap and try to turn the rotor button. If it turns dist gear has failed.
    If jammed up and zero backlash, it has failed.
    I wouldn't try to spin the engine. Use a socket and pull handle to try to turn it. If it turns, it might be salvageable. You'll still have to pull it and check and clean up.
    Hope it works out!


    Sent from my SM-G965U using Tapatalk
     
  10. Saab84mw

    Saab84mw Newbie

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    Time to start a new thread as soon as I get my truck back home the plan is to pull the engine and have a local machine shop rebuild it for me.
    I was pricing around a long block for the truck but after talking to the machine shop I’m just gonna have them rebuild it upgrade the cam possibly do a 411 computer swap maybe some Headers and a tune with a EGR delete so will be needing some help with the computer swap and tune.
    And also starting a building thread on the suburban.
     

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