4.3L wont start (spark problem)

Discussion in '1973-1987' started by Zeitgeist57, Jul 7, 2004.

  1. Zeitgeist57

    Zeitgeist57 Member

    Joined:
    Jul 4, 2003
    Messages:
    32
    Location:
    Naples
    My 1986 C10 has had some serious problems with not being able to start. It turns over and over and over just fine, but I can't seem to make it catch a spark. It's worked on and off in the past, but now for the past two days it won't catch. It feels like the electrical system is not giving any power to the distributor, or the distributor IS getting the signal and not knowing what to do with it.

    I've replaced: Coil, cap, rotor, spark plugs, sparkplug wires, ignition switch (mounted on top of the steering column; operated by a rod connected to the key ignition cylinder)

    I've had tested: Ignition module in distributor, pickup unit in distributor.

    So far, everything appears to be in spec, but it still won't spark. Can there be a relay I'm missing? Are there condensers in the HEI distributor that need replacing? (would that even affect it?)

    VERY frustrating x( x( x(
     
  2. cowboy

    cowboy Member

    Joined:
    Dec 8, 2001
    Messages:
    382
    Have you made sure that you have power to the coil? try runing a wire fromthe battery positive side to the positive side of the coil and turn it over and it should start.
    Cowboy
     
  3. eugene68

    eugene68 Member

    Joined:
    Jan 16, 2004
    Messages:
    60
    Location:
    phoenix u.s.
    Hello, just a couple things you can check..
    1.does your distributor turn? (the rotor) take the cap off and crank the engine.. if the distributor/rotor doesn't turn you have a broken timming chain/belt
    it that is o.k.
    2. run a hotwire from your battery right to the + side of your distributor cap and crank it over.if this works you have a problem somewhere in your wire..( the wire going to your distributor should be reading at least 12 volts with the key in the run position)

    My 77 blazer was doing the same thing.. It would crank but no fire..It would come and go drove me nuts... with the old wiring and replacing the ignition switch, I had to ad a hot wire to it to make it work.. it eventually fixed itself don't know why or how.. something with the combination of a new switch and slop in the steering colum I guess... must have self adjusted itself .
    Good luck. hope this helps you out. let us know if it does..
    eugene
     
  4. Zeitgeist57

    Zeitgeist57 Member

    Joined:
    Jul 4, 2003
    Messages:
    32
    Location:
    Naples
    I put another carb on (while my friend rebuilds the original Q-Jet) and it started and ran perfectly this morning. Now, it won't run. I tried to bridge the battery to the distributor and no effect. Not even a sputter. (GREAT IDEA, THOUGH!)

    Now, the battery is almost dead...I have to go and charge it up now.:-(

    I'm thinking it must be the carb. I'm going to try a few more things just to be sure...

    PLEASE GIVE ME OTHER SUGGESTIONS :) !!!
     
  5. cowboy

    cowboy Member

    Joined:
    Dec 8, 2001
    Messages:
    382
    well you alt. might be bad if you run it in the morning and later that day it wouldn't start casue the battery is low. um just keep fiddling with it.
    cowboy
     
  6. eugene68

    eugene68 Member

    Joined:
    Jan 16, 2004
    Messages:
    60
    Location:
    phoenix u.s.
    If your engine seems to run right really well right after the battery is charged but seems to get worse the longer it runs try this,
    pull off your positive battery wire (don't let it touch anything!!)
    if the engine dies as soon as you pull it off the battery, then your alternator is bad...the battery starts the engine, the alternator is supposed to provide the current to keep it running.

    good luck..
    (you might try an eldelbrock--carberator.. I have had excellent luck with them. easy to tune.. very forgiving carb)
    eugene68
     
  7. 84inArk

    84inArk Guest

    Might want to check your Ground to frame to your block. I had the same problem & pulled everything of and had it tested. Battery, alt., starter, NEW battery. Spent 8 hours doing this. Then 15 Sec. on my ground wire. Fired right off. Never a problem again



    Good Luck
     

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