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308 QV missing one cylinder when cold

Discussion in 'Technical Q&A' started by keithjallen, Jul 11, 2005.

  1. keithjallen

    keithjallen Rookie

    Feb 19, 2004
    25
    Surrey England
    Full Name:
    Keith Allen
    I have a Mondial 308QV which runs on 7 cylinders when cold. Cyl 1 on the rear bank appears not to be firing (established by pulling off plug leads) when cold but seems to come in when temperature is normal. I have tried changing the plug lead but had no effect. Any ideas would be greatly appreciated. Thanks.
     
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  3. Red Cab

    Red Cab Rookie

    Jul 10, 2005
    2
    Greenville, SC
    Full Name:
    Bob Barreto
    Had the same problem with my '85 QV. Could have been two things. 1st was that there's an automatic cold start in the FI system (a choke) that goes sour. Second was dirty injectors. Fixed both. No problems. Easy fix. Hope that helps.

    Bob
     
  4. matteo

    matteo F1 World Champ

    Aug 1, 2002
    13,748
    On a plane somewhere
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    Heir Butt
    I would second redcab on this. I would suspect a faulty injector.
     
  5. barcheta

    barcheta F1 Rookie

    Nov 15, 2003
    3,705
    I was told by a ferrari mechanic to also look at the wire to the cylinder in question. He suggested cutting the end where it goes into the distributor and re-terminating. While your at it might as well look inside the distributor to make sure you are making proper contact with the rotor.
     
  6. 208 GT4

    208 GT4 Formula 3

    Dec 27, 2003
    1,700
    Brighton (UK)
    Full Name:
    Dan
    I would suggest checking if #1 is actually sparking or not when cold. If it's sparking but not firing then it could be fuelling, if no spark then Ignition is the problem.
     
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  8. keithjallen

    keithjallen Rookie

    Feb 19, 2004
    25
    Surrey England
    Full Name:
    Keith Allen
    It is definitely sparking. How do I check the injector and this cold start device? Any ideas? Thank you.
     
  9. matteo

    matteo F1 World Champ

    Aug 1, 2002
    13,748
    On a plane somewhere
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    Heir Butt
    Pull the injector and get it checked or replace it.
     
  10. 208 GT4

    208 GT4 Formula 3

    Dec 27, 2003
    1,700
    Brighton (UK)
    Full Name:
    Dan
    I think the QV has Bosch K-Jetronic FI? If so, then the cold start is an extra injector that feeds all cylinders. So I would think it more likely to be a problem with the injector on #1 as the others have said.
     
  11. Verell

    Verell F1 Veteran
    Consultant Owner

    May 5, 2001
    7,000
    Groton, MA
    Full Name:
    Verell Boaen
    CIS injectors are tested by connecting them to a source of liquid under pressure & observing the flow quantity & spray pattern. BOSCH makes a tester specificly for these injectors, & there are also aftermarket testers out there.

    Too bad you 're not here in MA as I have a BOSCH injector tester/cleaner.
     
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