348 intermittent power loss | FerrariChat

348 intermittent power loss

Discussion in '348/355' started by hercfe, Jun 13, 2015.

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  1. hercfe

    hercfe Karting

    Apr 21, 2015
    194
    Northeast US
    Full Name:
    Ben
    Gentlemen,

    Thoughts on an intermittent problem. 1994 348 Spider, very infrequent power loss problem. Occasionally, the car seems to loose the right bank. Noticeable power loss, sometimes slow down lights, but not always. Always goes away with a quick cycling of the ignition key. Does not reoccur at any noticeable interval or driving condition, other than maybe at lower RPM's, although I do not lug the motor. This is very infrequent, and so far just annoying; but, annoying can quickly lead to really bad... Any ideas?
     
  2. Ferraripilot

    Ferraripilot F1 World Champ
    Owner Project Master

    May 10, 2006
    17,915
    Atlanta
    Full Name:
    John!
    Remove then clean the mass airflow sensor with the specific airflow sensor cleaner. That should do the trick.
     
  3. bikz

    bikz Formula 3

    Mar 2, 2012
    1,043
    Malaysia
    is it advisable to clean the MAFs if there are no issues? my brother has been at it cleaning his MAFs on his car and it got me thinking should it be done or not? or don't touch something till its giving some issues? is MAF cleaning a periodical maintenance procedure which shld be done?
     
  4. m.stojanovic

    m.stojanovic F1 Rookie
    Silver Subscribed

    Dec 22, 2011
    3,297
    Serbia - Niš
    Full Name:
    Miroljub Stojanovic
    The problem could also be caused by bad contacts in the MAF connectors. Unplug and clean the pins and the sockets. If you use a contact cleaner spray on the sockets, leave them unconnected for some time to dry (cleaner spray cools parts rapidly which causes moisture condensation which, if you connect the plug immediately, gets trapped inside causing further corrosion). I normally use a cotton bud dipped in Zippo lighter fluid to rub the pins and a narrow cut piece of thin cardboard which I push in and out of each socket a number of times.

    For a quick check, you can pull the connectors in and out a number of times - self cleaning.
     
  5. Bertil

    Bertil Karting
    Owner

    Sep 8, 2012
    199
    Stockholm Sweden
    Full Name:
    Bertil Palmblad
    As the MAF's are self cleaning, I think IMHO, your problem is the thermocouples or the CAT ECU.
    Change side of the thermocouples. If it's still your right bank shutting down, change side of the CAT ECU's. probably it will be the left bank shutting down.....
    Bertil
     
  6. Pangea

    Pangea Formula Junior

    Mar 27, 2011
    442
    UK
    Full Name:
    Nick
    This is where I would be looking. Good advice.
     
  7. cf355

    cf355 F1 Rookie

    Feb 28, 2005
    4,208
    Full Name:
    chris
    Check for any codes. Clean all the connectors in the engine bay with an aerosol electrical contact cleaner (use an air compressor to blow dry if you have one).....or use a swab or leave open to dry as others have suggested. Definitely clean the MAF's with a specific
    product for this application. Drive it and if the problem returns.... then consider swapping components to see if you can identify the errant problem.
     
  8. alexjack

    alexjack Karting

    Jun 29, 2013
    67
    New England
    Full Name:
    Don
    I had the same problem. I'd lose power, then cycle the key, then everything ok again. My tech replaced a faulty cat temp ecu. Problem fixed.
     
  9. mad dog

    mad dog Formula Junior

    Jan 5, 2006
    875
    suffolk uk
    Full Name:
    andrew
    All the above, but i also had once a dodgy connection to one of the main ecu.
     
  10. hercfe

    hercfe Karting

    Apr 21, 2015
    194
    Northeast US
    Full Name:
    Ben
    Thanks guys! I was thinking the exhaust ECU's too. Question, the "my348" site suggests sealing the ECU's with Permatex silicone, as part of the "post purchase prepping". I'm a little confused as to what to seal, I haven't pulled one yet, but aren't these sealed units anyway...? What am I sealing?? I am also planning on doing the Stabilant 22a on all the electrical connectors. Did the ECU reset yesterday, but haven't had it out yet.
     
  11. F355Bob

    F355Bob Formula 3

    Had it happen on my 95F355 Was a bad cat ECU.
     
  12. angelis

    angelis F1 Veteran
    Owner

    Jun 18, 2004
    6,400
    London, England
    Full Name:
    Sy
    Same here. Bad CAT ECU.

    Ended up removing both of them.
     
  13. Bertil

    Bertil Karting
    Owner

    Sep 8, 2012
    199
    Stockholm Sweden
    Full Name:
    Bertil Palmblad
    Same for me Doris. When, not if, you have to replace the ECU's, be sure you get the newer ECU's. The green ones.
    Bertil
     
  14. angelis

    angelis F1 Veteran
    Owner

    Jun 18, 2004
    6,400
    London, England
    Full Name:
    Sy
    Mines a 1994 GTB so they are the latest ECU's.

    PS. Someone on this forum actually came up to me at an event and thought the Doris thing was real :D
     
  15. jlclt348

    jlclt348 Karting

    Jul 7, 2013
    209
    Ridgefield, CT
    Full Name:
    Justin
    For my car it was a bad cat temp sensor.
     
  16. John_K_348

    John_K_348 F1 Rookie

    Sep 20, 2013
    2,757
    Boston, MA
    Full Name:
    John E. Kenney
    Yup new exhaust ecus. 355 vintage, green silicon. You can try DIY but chasing the condensation may cost as much in labor.
     
  17. hercfe

    hercfe Karting

    Apr 21, 2015
    194
    Northeast US
    Full Name:
    Ben
    Must have been dirty MAF's. Pulled them both and cleaned, hasn't happened since... Thanks for the advice!!
     
  18. John_K_348

    John_K_348 F1 Rookie

    Sep 20, 2013
    2,757
    Boston, MA
    Full Name:
    John E. Kenney
  19. bayferrari

    bayferrari Karting
    Silver Subscribed

    Mar 10, 2011
    95
    Bay Area
    Full Name:
    William
    How do you know if you are getting the newer ECU's, are these standard from Ricambi, or do you have to specify.
     

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