86 3.2 mondial Runs rough | FerrariChat
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86 3.2 mondial Runs rough

Discussion in 'Technical Q&A' started by ddiggler, Jul 23, 2023.

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  1. ddiggler

    ddiggler Karting

    Nov 24, 2017
    77
    Full Name:
    doug nelson
    #1 ddiggler, Jul 23, 2023
    Ran great 10 days ago. Started yesterday and seems to idle fine. Give it some gas and runs rough and lacks power. Any ideas? Thanks. Doug.
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,673
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #2 Steve Magnusson, Jul 23, 2023
    What version? US? euro? CH? Something else?
     
  3. ddiggler

    ddiggler Karting

    Nov 24, 2017
    77
    Full Name:
    doug nelson
    #3 ddiggler, Jul 23, 2023
    U.S. version.
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,673
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #4 Steve Magnusson, Jul 23, 2023
    In that case, the first thing to check is if the Frequency Valve is correctly "buzzing/vibrating" when the engine is running (it should "buzz/vibrate" whenever the fuel pump is running -- just touch it with a fingertip). If it isn't = you need to investigate the Protection Relay system (that's what supplies +12V to run the Injection ECU which runs the FV).
     
  5. ddiggler

    ddiggler Karting

    Nov 24, 2017
    77
    Full Name:
    doug nelson
    #5 ddiggler, Jul 23, 2023
    I will do that. I also saw a previous post of someone recommending to change the battery. It is old and I have had to charge it if it sits for much more than a few weeks. Seems strange but could that also be a possibility? Thank you for being so quick with you recommendations.
     
  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,673
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #6 Steve Magnusson, Jul 23, 2023
    Weak battery wouldn't be high on my list of suspects for your symptom (especially if the starter motor cranks well). Easy enough to test. Just measure the DC voltage between the two battery terminals when the engine is running at idle. Should be something like 13V -- if it was less than 12V that would be a concern.
     
  7. ddiggler

    ddiggler Karting

    Nov 24, 2017
    77
    Full Name:
    doug nelson
    #7 ddiggler, Jul 23, 2023
    Hi Steve. Before I posted this thread I checked the air filter and noticed the sleeve coming off of it to the air intake has no clamp and didn't appear to be seated very well. I slid it back on but didn't start the car. Anyways, I just went out to start it and check the Frequency valve and it started right up and is very responsive now. The valve is vibrating when I touched it. I wouldn't think the air intake sleeve would effect it but I am completely confused now. Can the Frequency Valve intermittently work?
     
  8. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,673
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #8 Steve Magnusson, Jul 23, 2023
    The way that you describe the "sleeve" not fitting well, it doesn't seem like that would be related to this problem. But, to be clear, an air leak in the intake path from part 25 to part 33 here:

    https://www.ferrariparts.co.uk/diagram/ferrari/32-mondial---cabriolet/017-air-intake-and-manifolds

    shouldn't affect the engine's runability, but an air leak at either end of hose 29 would.

    If the FV is working intermittently, it's most often caused by the Protection Relay system working intermittently. Now that you've calibrated yourself for how the FV "feels" when things are working well, if the trouble happens again, give the FV another feel to see if it's different. Unfortunately, if it ain't broke, it don't need fixing ;).
     
  9. ddiggler

    ddiggler Karting

    Nov 24, 2017
    77
    Full Name:
    doug nelson
    #9 ddiggler, Jul 24, 2023
    I did realize that when I pulled the air filter out I pushed open the butterfly valve for the air intake under the filter. I'm thinking that maybe it wasn't opening and restricting the air intake effecting the air/fuel mixture. Took it for a drive tonight and it runs great. I had a previous car that had a recall for the mass air sensor. Carbon buildup would restrict it from opening properly. I hope the problem is solved. Thank you very much for your input. I have definitely learned alot from you post. Thank you again. Doug.
     
    Ferrari Tech likes this.

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