Idle not quite right | FerrariChat

Idle not quite right

Discussion in '348/355' started by GWARREND, Jun 13, 2022.

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  1. GWARREND

    GWARREND Formula Junior

    Sep 23, 2012
    525
    Ontario, Canada
    Full Name:
    Greg
    #1 GWARREND, Jun 13, 2022
    Last edited: Jun 13, 2022
    My 355 at cold startup sounds normal. After 5 mins of driving (warm), the idle does not sound quite right...like a random miss. So far... no CELs. I installed new air filters, cleaned the MAF, Idle Control Valve...feels like it improved but still something not quite right. Once engine revved above 1500RPM or moving everything completely normal.

    The engine was last our 2019, 9K miles ago. Now thinking spark plug wires after reading on FChat about wires causing similar symptoms. Wires are Beru and look to be in good shape.

    Appreciate ideas and suggestions:

    https://photos.app.goo.gl/CoP57k6p9ftALwUS7
    https://photos.app.goo.gl/YYUkxzu2T8Q3qQzt9
     
  2. jjtjr

    jjtjr Formula Junior

    Aug 29, 2016
    676
    Vermont
    Full Name:
    john truskowski
    #2 jjtjr, Jun 14, 2022
    Not sure if this is a 2.7 car or 5.2, but I just ran into a misfire at idle with my 2.7. After diagnosing all secondary ignition components, it turned out to be the plugs.
     
  3. Racing Snake

    Racing Snake Rookie

    Dec 20, 2006
    43
    Lincolnshire, UK
    #3 Racing Snake, Jun 15, 2022
    Interesting, I've got a similar issue, so am watching this thread.
    however mine had a full service and belt change before I got the car (6 months, now 700miles ago).
    So I'd like to think my plugs are good.

    I've got full decats on, so I wondered if it was related to that? (mine is a 99 F1).
     
  4. 26street

    26street Formula Junior

    Jan 30, 2021
    343
    Westchester New York
    Full Name:
    Mark k
    #4 26street, Jun 15, 2022
    Did you try using a fuel system cleaner in the tank yet ——this should clean the injectors and possibly the valves if not pass the point where they will need to be service



    Sent from my iPhone using FerrariChat
     
  5. spaghetti_jet

    spaghetti_jet Formula Junior

    Jan 5, 2005
    854
    Europa
    Full Name:
    Bob
    #5 spaghetti_jet, Jun 15, 2022
    First thing I always do now when tackling unstable idling issues is to check all rubber hoses & o rings etc. for air leaks into the plenum. Then I check all vac lines to the FPRs etc. Only once I know that the the intake system is sound do I start troubleshooting. The F355 has a multitude of places unmetered air can get in and play havoc with getting a decent, stable idle.
     
    Zamboniman308 likes this.
  6. Zamboniman308

    Zamboniman308 Formula Junior

    Feb 2, 2020
    463
    Chicago IL
    #6 Zamboniman308, Jun 15, 2022
    This x100.. and don't be afraid to toss a fuel pressure gauge on it. Quick check that can reveal a lot.
     
    spaghetti_jet likes this.

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