84 308 Quatro injectors clogged? | FerrariChat

84 308 Quatro injectors clogged?

Discussion in 'Technical Q&A' started by Quasimotor, Sep 14, 2004.

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  1. Quasimotor

    Quasimotor Formula Junior

    Jan 4, 2004
    325
    Yonkers, NY
    Full Name:
    George Avgerakis
    Recently my 308 started running rough. At first it was only during warm-up. She'd idle slow and backfire as I backed it out of garrage. If I gently added gas, she'd jump from the slow idle of 500 RPM up to the normal 1100. If I ran it slowly, it would run at about half power and then suddenly kick into faster mode. I think it migh tbe a fouled injector, bad spark generator, what? Now, after about two weeks of casual driving it's always idling at 500, and is sluggish at the low revs.

    What's wrong with my baby and how can I fix her up?
     
  2. Ferrari_tech

    Ferrari_tech Formula 3

    Jul 28, 2003
    1,527
    UK
    Full Name:
    Malcolm W
    Could be a number of things fuel related - for example vacuum leaks, air flow sensor lever / control plunger not moving freely, cold control pressure outside tolerance, low fuel pressure.

    I would recommend that you check all the fuel pressures (including cold start injector and main injectors) and see what figures you come up with. If you need the pressure data I will post for you.

    Alternatively it could be ignition related, even something a simple as spark plugs, plug wires etc.
     
  3. ferrarifixer

    ferrarifixer F1 Veteran
    BANNED

    Jul 22, 2003
    8,520
    Melbourne
    Full Name:
    Phil Hughes
    Possibly running on only one bank of cylinders too.....

    That'd most likely be the old faithful crank sensor/connections messing around.

    Seems to be the most common recurring fault that I see on all K-Jet cars.
     
  4. brian.s

    brian.s F1 Rookie
    Professional Ferrari Technician

    Nov 3, 2003
    3,806
    Midwest
    Full Name:
    Brian
    It could also be related to the mixture control ECU/O2 sensor relay/fuse...
    I would have a clogged injector way down on my checklist. Start with the basics, first ignition then fuel. Search archives for things to look at, plugs/extenders/wires/cap/rotor/coil. Then on to fuel pressures/frequency valve et al.
    Once it is determined which system/bank/cylinder the fix is straightforward.

    good luck, brian
     

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