HEI question

Discussion in 'Troubleshooting & Diagnosis' started by rumrunner, Feb 2, 2008.

  1. TheFly

    TheFly Guest

    Isn't anyone reading???

    He just said the coil n modual was tested as good.
  2. rumrunner

    rumrunner New Member

    Jan 8, 2008
    Atlanta Georgia
    No, no tach, if it had no spark it would be easier to fix, but waek yellowish spark means not enough voltage, I don't know if the primary voltage is waek or not, has a brand new MAXX battery and it turns over fine.
    I can get a whole new HEI distributor on Ebay for about 80 bucks, better than chasing this, and it comes with a 65K coil, vac advance, the works.
    I took a look at the rotor, no burn through, I did see a piece broken but it looks like it was a cover for the metal strip from the center to the plug wire terminals, the cap has aluminum terminals so it's probably a cheapo unit, brass would be better.

    I would sure like to know what the problem is though, bugging me because it's gotta be something simple.
  3. 74RAT

    74RAT Veteran Member

    Dec 28, 2003
    ft. stockton,tx,usa
    seen the wire breakage before. also if the shaft bushing gets tooooooo worn and loose,, it can side load and not make good mag triggering on the loose side from too much clearance. easy check. pull the cap and rotor and move the shaft arround in every direction and look for clearance movement. should have no movement at that top bushing just under the pickup coil. can check p'up coil continuety with a volt/ohm meter as well. then check it to ground from each terminal. seen one of the dist. shafts worn through the bushing and into the pickup coil/windings and grounded it out once. that's probably a rare case to come across though. doesn't hurt to check. don't have to pull the dist. to do it. hope it helps and hope you find it.
  4. brick_haus

    brick_haus Veteran Member

    Oct 22, 2006
    Somis, Ca.
    Sometimes the module works fine when it's cold and intermittently, weak or not at all when hot. This may be why it tested goodon the bench. Replace it and dont forget the silicone grease when installing it. It acts as a heat transfer and helps them last longer. Nothing worst than paying $120 to get towed home from 50 miles out becaeuse of a $30 part... Ask me how I know...
  5. Rich 81 z28

    Rich 81 z28 Veteran Member

    Jun 4, 2007
    King George, Virginia
    I've also seen the pick up at the base of the dist go bad.. acted just like a bad module.
  6. TheFly

    TheFly Guest

    Yep, why I sa do the wires, ya know coil n modual is good, spark plugs are new, if new wire don't do it and ya got a full 12volts to the dizzy power wire [the big one] that all that is left. And to change it the whole dizzy has to come apart.

    I wouldn't buy the summit kit.

    Get the MSD external coil cap for HEI MSD-8401
    Get a Summit SUM-G5215 coil
    And get the Crane adjustable vac advance CRN-99600-1

    the GP Sorensen modual n pickup is a good one, they make em right.

    Then get a gold termanl cap n rotor from local place.
    Already will have new wires, all auto store can sell you just the coil wire.
  7. 77LT1

    77LT1 Veteran Member Lifetime Gold Member

    Jan 29, 2007
    Jax, FL
    Mine "tested" good when I KNEW it was the problem. YOU must not be reading. Mine would be fine cold but when warmed up it would fail. Changed the module and never had a problem with it again.

  8. brick_haus

    brick_haus Veteran Member

    Oct 22, 2006
    Somis, Ca.
  9. John Wright

    John Wright Veteran Member Lifetime Gold Member

    Aug 9, 2002
    Rustburg, Va
    Did ya look at the little carbon button between the coil and the rotor button?.. ;)
  10. TheFly

    TheFly Guest

    Go JW, I had one crack in half once.........

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