348 Persistent Misfire | Page 2 | FerrariChat
Buy

348 Persistent Misfire

Discussion in '348/355' started by Mike Ferrari, Mar 1, 2016.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

Page 2 of 2
  1. Mike Ferrari

    Mike Ferrari Rookie

    Jul 10, 2007
    7
    #26 Mike Ferrari, Mar 16, 2016
    Whilst the car was on test, they checked the temperatures of the exhausts with a thermal camera. The left bank was running much hotter than the right suggesting a lean mixture rather than the rich mixture the fowled spark plugs suggested... I'm still not sure about this point but facts are facts...

    Anyway, I have two new O2 sensors on order (best to fit in pairs). Once they are fitted, we can do some more tests and we'll know a little more...

    As I said previously, I'm hoping to run the car without the thermocouple ECU's, but I'm looking for proof that the car doesn't run on a default map when this 'change' is made...

    Hopefully another update coming soon!

    Thanks again!
     
  2. Jackie and bill

    Jackie and bill Formula Junior

    Nov 29, 2014
    795
    GB
    Full Name:
    William
    #27 Jackie and bill, Mar 16, 2016
    I am just taking a moment :), I take em were I can :D
     
  3. ///Mike

    ///Mike F1 Veteran

    Dec 11, 2003
    6,097
    Bugtussle
    #28 ///Mike, Mar 16, 2016
    Two things I can think of offhand that could explain wet/fouled plugs combined with higher exhaust temps:

    1) Significantly retarded ignition timing-- if the spark event is occurring late, combustion in the cylinders themselves may not be complete enough to keep the plugs clean and the remaining fuel may be burning in the exhaust, raising its temp.

    2) Advanced exhaust cam timing. This should show up in a comparison of compression readings. I thought you'd already done one but scanning back through the thread I didn't notice mention of it. I'd suggest checking compression on all 8 cylinders forthwith if you have not done so already. You've beaten your head against the wall for a while now so it might be time to reconsider the basics.
     
  4. Mike Ferrari

    Mike Ferrari Rookie

    Jul 10, 2007
    7
    #29 Mike Ferrari, Mar 16, 2016
    She's not completely out of the woods yet, but your point is well made Jackie & Bill! Thanks :)
     
  5. Jasonberkeley

    Jasonberkeley Formula 3
    Rossa Subscribed

    Apr 23, 2017
    1,348
    NW Corner, CT
    #30 Jasonberkeley, Jun 4, 2023
    What was the problem and solution?!
     
  6. steved033

    steved033 F1 World Champ
    Owner Silver Subscribed

    Apr 12, 2017
    10,339
    Atlanta, GA
    Full Name:
    Steve D.
    #31 steved033, Jun 4, 2023
    Do you have a misfire?

    Mine was 34 year old spark plug wires....

    sjd
     
    ernie likes this.
  7. Jasonberkeley

    Jasonberkeley Formula 3
    Rossa Subscribed

    Apr 23, 2017
    1,348
    NW Corner, CT
    #32 Jasonberkeley, Jun 4, 2023
    Yes- CYL 1-4 check engine light. Replaced ground wires, battery cables, relays, Oxygen sensors, etc...

    Plugs, plug wires, etc... all two years old.
     
  8. m.stojanovic

    m.stojanovic F1 Rookie
    Silver Subscribed

    Dec 22, 2011
    3,300
    Serbia - Niš
    Full Name:
    Miroljub Stojanovic
    #33 m.stojanovic, Jun 4, 2023
    Did you check fuel pressure?
     
  9. Jasonberkeley

    Jasonberkeley Formula 3
    Rossa Subscribed

    Apr 23, 2017
    1,348
    NW Corner, CT
    #34 Jasonberkeley, Jun 5, 2023
    Yup. The following were also checked and were all fine:

    - Coil Packs
    - Fuel Pressure
    - Fuel injectors / wiring
    - Mass air flow sensors / wiring
     
  10. Ferrarium

    Ferrarium F1 Veteran
    Sponsor Rossa Subscribed

    Jul 28, 2018
    5,728
    Central NJ
    Full Name:
    Eric
    #35 Ferrarium, Jun 5, 2023

    What is the code your getting?
     
  11. Pangea

    Pangea Formula Junior

    Mar 27, 2011
    442
    UK
    Full Name:
    Nick
    #36 Pangea, Jun 5, 2023
    Crank sensor / wiring for that bank..???
     
Page 2 of 2

Share This Page