308 QV missing one cylinder when cold | FerrariChat

308 QV missing one cylinder when cold

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

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  1. keithjallen

    keithjallen Rookie

    Feb 19, 2004
    25
    Surrey England
    Full Name:
    Keith Allen
    #1 keithjallen, Jul 11, 2005
    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.
     
  2. Red Cab

    Red Cab Rookie

    Jul 10, 2005
    2
    Greenville, SC
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    Bob Barreto
    #2 Red Cab, Jul 11, 2005
    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
     
  3. matteo

    matteo F1 World Champ

    Aug 1, 2002
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    #3 matteo, Jul 11, 2005
    I would second redcab on this. I would suspect a faulty injector.
     
  4. barcheta

    barcheta F1 Rookie

    Nov 15, 2003
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    Jim
    #4 barcheta, Jul 11, 2005
    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.
     
  5. 208 GT4

    208 GT4 Formula 3

    Dec 27, 2003
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    #5 208 GT4, Jul 11, 2005
    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.
     
  6. keithjallen

    keithjallen Rookie

    Feb 19, 2004
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    Surrey England
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    Keith Allen
    #6 keithjallen, Jul 11, 2005
    It is definitely sparking. How do I check the injector and this cold start device? Any ideas? Thank you.
     
  7. matteo

    matteo F1 World Champ

    Aug 1, 2002
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    #7 matteo, Jul 11, 2005
    Pull the injector and get it checked or replace it.
     
  8. 208 GT4

    208 GT4 Formula 3

    Dec 27, 2003
    1,764
    Brighton (UK)
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    Dan
    #8 208 GT4, Jul 11, 2005
    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.
     
  9. Verell

    Verell F1 Veteran
    Consultant Owner

    May 5, 2001
    7,017
    Groton, MA
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    Verell Boaen
    #9 Verell, Jul 11, 2005
    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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