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Intermittent ignition problem on Mondial QV

Discussion in 'Technical Q&A' started by FasterIsBetter, Jul 27, 2004.

  1. FasterIsBetter

    FasterIsBetter F1 Veteran

    Jul 22, 2004
    5,844
    NoNJ/Jupiter FL
    Full Name:
    Steve W.
    I recently got an '84 Mondial QV, 19K miles, Euro car. The first few days driving, the car ran fine, nice and powerful. Then, the other evening I started the car up and it was as if one bank of the engine was gone. No power, lots of hesitation. When I lifted my foot off the gas, it sputtered and backfired, and when I put my foot down on the clutch and took the other off the gas, it idled right down to almost nothing and stalled. Today, when I started it, it was okay when cold, but then started acting up once the car warmed up.

    When I got the car, the local mechanic, a well-respected Ferrari guy, who had been caring for the car told me it needed ignition wires and probably distributor caps and rotors. I picked up a set of replacement wires and took the car in today to have them changed. He feels that's the source of the problem.

    Is there something else that would likely be causing these symptoms? In my '72 Jaguar V-12, there was an ignition amplifer for the electronic ignition that was prown to failure when hot. Cool it down, and the car would be fine. When it would get hot, it would fail. Anything like that happen with the ECU or eletronic ignition packs on these cars? Something else I should be concerned about?

    Thanks,
    Steve W.
     
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  3. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    19,896
    Texas
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    Steve Magnusson
    Steve -- Check the ignition section of your OM (it'll be in about the page 72~75 area depending on which OM version) -- it's got a good overall description + schematic. And, yes, there are plenty of items that could cause just one bank to go out (ECU, TDC sensor, coil, distributor). You've essentially got two separate ignition systems for each bank so (if the distributors aren't the problem) you can swap the common electrical components (ECU, TDC sensor, coil ) one at a time and see if the problem follows the component to the other bank (if you're inclined to DIY). Here a partial shot from the US 308_84 OM, but your "euro" (do you know if it's a CH version or just Standard?) will be the same ignition-wise. Good luck with the repair...
     
  4. KKSBA

    KKSBA F1 World Champ
    Rossa Subscribed

    Oct 31, 2003
    13,955
    SBarbara-La Jolla CA
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    KKSBA
    Two quick things to check:

    Fuel pump fuse, wiggle it back and forth to make sure it is snug and making a good connection.

    Spark plug extenders. These are plugged into the plug wires that then reach down into the head and plug onto the spark plugs themselves. They fail without notice and will get pinholes in them that ground out the spark potential. Pull them out (red or black) and check if they have any small burn marks. Also, if you see any black tape wrapped around them, it likely means someone forgot to replace a previous problem extender. They are cheap.

    These two items are quick checks. Other than that I will defer to the more experienced guys.
     
  5. FasterIsBetter

    FasterIsBetter F1 Veteran

    Jul 22, 2004
    5,844
    NoNJ/Jupiter FL
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    Steve W.
    Well, I got some feedback from the mechanic. Apparently, one of the two rotors had decided to give up the ghost. He said that when he opened the rear distributor, the rotor was cracked. We are replacing both distributor caps, rotors and the wires, and hopefully that will solve the problem.

    Thanks for the input and I'll let you know if that solves the problem.

    Regards,
    Steve W.
     
  6. tifosi

    tifosi F1 Veteran
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    Sep 5, 2001
    5,382
    texas
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    Tom D
    wait till you see the bill :(
     
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  8. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    17,176
    USA
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    Hugh G. Rection
    Save the old caps...they are still work $$$ if they are serviceable. Like Tifosi said..wait till you see the bill. I think the cheapest you can get authentic Marelli caps is from Ferrari UK, and the will still set you back $275 each or something (FNA dealers get $450)....don't get the reproductions...someone posted last year of problems with them. The are also priced around $250 to $275.
     
  9. KKSBA

    KKSBA F1 World Champ
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    Oct 31, 2003
    13,955
    SBarbara-La Jolla CA
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    KKSBA
    The good news is that when your done with the repair a major part of your ignition system will be brand new and should give you a lot of future enjoyment!
     

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