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Thread: Mysterios electrical problem on Fiero GT

  1. #1
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    Mysterios electrical problem on Fiero GT

    I've got an 86 fiero gt with a v6. It starts sometimes and sometimes it doesn't. It has progressivly gotten worse. In my process of elimination I have replaced the dist cap, rotor, plug wires, and finally the coil. It still does it, at first I thought a wire (perhaps in the coil) was expanding when warm because it was doing it when it got warmed up. Now when it quits it can take up to 3 weeks before it will start again, there went the expanding wire theory. Since then I replaced the coil etc. and it still does it. Any ideas guys?
    thanks

  2. #2
    Senior Member FerrariFan's Avatar
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    Re: Mysterios electrical problem on Fiero GT

    starter solonoid maybe.
    Even the longest journey begins with the first step.

  3. #3
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    Re: Mysterios electrical problem on Fiero GT

    When it won't start.. Did you check for power at the fuel pump.. fuel pressure.. power at the coil... spark leaving the coil..
    if its auto. check your neutral saftey switch to see if its cutting power to computer. check all the fuses and if all check out good.. run your hand up and down the fuses to check for shorts. When it won't start is the perfect time to run all your tests. because when it does start the short or faulty wire is not breaking the curcuit. And if still no luck.. call your insurance and add full coverage and light er' up.
    Just smart enough to be very Dangerous

  4. #4

    Re: Mysterios electrical problem on Fiero GT

    Like EEExotic says, Start with the easy stuff. Pull the coil wire out of the dist cap and leave it in the coil. Hold it 1/2" from bare engine metal and watch for sparks. If no spark it is still an ignition problem. If you have spark it is therefore a fuel problem. Listen for the 5 seconds of noise from the fuel pump at 'key on' .
    Post your results and we can give you a step by step test procedure.

  5. #5
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    Re: Mysterios electrical problem on Fiero GT

    ??? Thanks 4 the replies. It's not the starter, it turns fine whether it starts or not. The coil does not spark when it in the non starting mode. The fuel pump does make its little noise everytime the key is turned on.

  6. #6
    Senior Member cowans's Avatar
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    Re: Mysterios electrical problem on Fiero GT

    You most likely need to replace the ignition module. They are notorious for intermittant failures. Apparently the heat in the rear 'cooks' the module, as well as V6 alternators! The people on Pennocks.com swear by using a GM replacement module, it is supposed to use better components. Allot of owners carry a spare module in their trunk for just such a problem!
    good luck,
    Sandy

  7. #7

    Re: Mysterios electrical problem on Fiero GT

    I agree with sandy, best to swap that out.

  8. #8
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    Re: Mysterios electrical problem on Fiero GT

    Thanks Sandy I'll try that next.

  9. #9
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    Re: Mysterios electrical problem on Fiero GT

    one simple thing I found sometimes on kit installs ...is there is a braided ground stap that runs from the engine and bolts to the firewall underneath the orginal fiero rear hood hinges when you remove the fiero deck lid this strap falls down the back of the engine if you forget to bolt it back on, the engine loses its main ground and tries to find a ground thru some other path often with not the best results ,this strap can often rot out or be very corroded too ....just in general fieros are getting pretty old and poor grnds or rust around the grnd connections are often the reason for allot of weird electrical problems .. you could try taking just one jumper cable run it from the neg side of the bat to a real clean bare spot on the block as a test .john

  10. #10
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    Re: Mysterios electrical problem on Fiero GT

    Thanks for all the help, I just got done putting in the new ignition module and found a lot of rust and corrosion on the prongs of the inner plug that plugs onto the module. After cleaning them the problem seems to be solved. This thing is finally ready to be sold.

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