Engine misfire
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Engine misfire

  1. #1
    Attack Republican scottwizer's Avatar
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    Default Engine misfire

    Helping a buddy out on his engine. It is a 540 BBC with an 8-71 blower that is teflon stripped. It has an enderle bird catcher, Mallory magneto.
    The motor was recently freshened up with new rings and bearings. We are fighting a misfire. Upon startup the number one cylinder started missing with raw fuel out of the exhaust. All of the other cylinders are firing normally. We checked compression and did a cylinder leakdown test. Everything tested fine and all cylinders are within 2 % of each other. We checked spark and timing, and all is good. As a precaution we put in new plugs and wires. Still can't get that cylinder to fire. The plug is wet and shows no evidence of firing at all.
    I am a newbie when it comes to blown injected applications. None of the tune was changed after the motor was freshened up. Any ideas on what else to check?
    "Second place is the first loser...."
    Thank God I own a V-drive and not a jet...

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  3. #2
    Senior Member EVILFORCE's Avatar
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    Quote Originally Posted by scottwizer View Post
    Helping a buddy out on his engine. It is a 540 BBC with an 8-71 blower that is teflon stripped. It has an enderle bird catcher, Mallory magneto.
    The motor was recently freshened up with new rings and bearings. We are fighting a misfire. Upon startup the number one cylinder started missing with raw fuel out of the exhaust. All of the other cylinders are firing normally. We checked compression and did a cylinder leakdown test. Everything tested fine and all cylinders are within 2 % of each other. We checked spark and timing, and all is good. As a precaution we put in new plugs and wires. Still can't get that cylinder to fire. The plug is wet and shows no evidence of firing at all.
    I am a newbie when it comes to blown injected applications. None of the tune was changed after the motor was freshened up. Any ideas on what else to check?
    Maybe a vacuum leak? Spray some carb clean around intake. Could also be a internal leak on manifold.
    No Fool Like A Old Fool is there?

  4. #3
    Senior Member Ronboats's Avatar
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    Maybe check for continuity from inside the dist. cap to the plug end of the wire. Might be a problem with the cap.

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  6. #4
    Attack Republican scottwizer's Avatar
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    I will suggest to him to try that. I figured with pressure from the blower that if it did have a blown gasket that it would lean misfire... I will also inspect the cap. Thanks!
    Jason
    "Second place is the first loser...."
    Thank God I own a V-drive and not a jet...

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