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348 running issue

Discussion in 'Technical Q&A' started by Will348, Dec 5, 2018.

  1. Will348

    Will348 Rookie

    Dec 5, 2018
    26
    Scotland
    Full Name:
    William
    Hello chaps

    My 348 has an issue and im posting here in the hopes someone can give me an idea of the “common” issues these cars have which could help identify what is wrong

    Last drive out in my car the power just went, Ive taken the car to some mechanic friends and each one of them sais there doesnt sound to be anything majorly wrong with the car, possibly fuel or electrical.

    The car hasnt dropped a bank, Put your foot down in 1st gear and its like your taking off in 4th the powers just flat

    Today im going to replace all the relays and go from there, any help will be greatly appreicated
     
  2. Ricambi America

    Ricambi America F1 World Champ
    Sponsor Owner

    Dec 7, 2003
    15,183
    Winston Salem, NC
    Full Name:
    Daniel
    Are you certain it hasn't dropped a bank?

    1) Is one of the slowdown lamps illuminated?
    2) Do the slow-down lamps actually have bulbs installed? You'd be surprised what some folks do to these cars...
     
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  3. Will348

    Will348 Rookie

    Dec 5, 2018
    26
    Scotland
    Full Name:
    William
    3 seperate mechanics have looked at it and all said both banks were running,

    the slow down lights light up on ignition but then dissapear after a few seconds

    May or may not be related but the front right headlight bucket stopped going all the way down the same night the problems with the engine started, aswell as some other electrical faults which have now been resolved other than the headlight, speaking of which has today developed another fault whereby both headlights are out of sync, the bucket on the right is up when the left bucket is down
     
  4. Will348

    Will348 Rookie

    Dec 5, 2018
    26
    Scotland
    Full Name:
    William
    The issue is permament, it a struggle to build up speed in the car so limp mode comes to mind

    When its been revved, once you stop reving the motor tends to stall

    Today ive replaced the relays, disconnected the cat ecus and disconnected the maf sensors, aswell as a ECU reset, still have the problem
     
  5. Wade

    Wade Two Time F1 World Champ
    Rossa Subscribed Owner

    Mar 31, 2006
    23,800
    East Central, FL
    Full Name:
    Wade O.
    Too many questions... e.g. where are you located, how long have you owned the car, any other recent work/events (theft, crash, flood, etc.), are your mechanics knowledgeable on the 348..........
     
  6. Wade

    Wade Two Time F1 World Champ
    Rossa Subscribed Owner

    Mar 31, 2006
    23,800
    East Central, FL
    Full Name:
    Wade O.
    Year? 2.5 or 2.7? Checked the codes? Do you have an Owners Manual, a Workshop manual?
     
  7. Will348

    Will348 Rookie

    Dec 5, 2018
    26
    Scotland
    Full Name:
    William
    United kingdom
    12 years
    One of the mechanics is a close friend whos worked on my car since i bought it.
    1993 2.7
    Yes i have the workshop manual online
     
  8. Wade

    Wade Two Time F1 World Champ
    Rossa Subscribed Owner

    Mar 31, 2006
    23,800
    East Central, FL
    Full Name:
    Wade O.
  9. Will348

    Will348 Rookie

    Dec 5, 2018
    26
    Scotland
    Full Name:
    William
    Yes in neutral it revs freely,maybe a little flat but you can get the engine high in the rev range
     
  10. Will348

    Will348 Rookie

    Dec 5, 2018
    26
    Scotland
    Full Name:
    William
    Sometimes after giving it a rev, the revs will drop so low it stalls, not every time but most of tbe time. This also happens out on the road
     
  11. Will348

    Will348 Rookie

    Dec 5, 2018
    26
    Scotland
    Full Name:
    William
    No codes yet, my car didnt have the ecu test button or loom

    On order

    Thanks
     
  12. pnicholasen

    pnicholasen Formula 3

    Jan 14, 2011
    1,252
    South of Philly
    Full Name:
    Paul Nicholasen
  13. yelcab

    yelcab F1 Veteran
    Consultant

    Nov 29, 2001
    8,887
    San Carlos, CA
    Full Name:
    Mitchell Le
    I would not ignore that electricity - headlight problem. Start with making sure your battery is good, and the alternator is good.
     
  14. Will348

    Will348 Rookie

    Dec 5, 2018
    26
    Scotland
    Full Name:
    William
    No i havent performed a compression test!

    The plugs were replaced in feb along with a new battery, ive done an alternator test and im getting just over 14v so thats ok.

    Im not ignoring it, can anybody see how the two could possibly be related or merely a coincidence the issues happened at the same time?

    Ive also been advised that although both banks are running when idling/revving, one could be dropping when driving, although the engine doesnt sound happy to start and still cuts out when the revs drop when in neutral so i really do not think i have a bank dropping under load?
     
  15. yelcab

    yelcab F1 Veteran
    Consultant

    Nov 29, 2001
    8,887
    San Carlos, CA
    Full Name:
    Mitchell Le
    Was any work (maintenance, repairs) done to the car just before the problem begin?
     
  16. Will348

    Will348 Rookie

    Dec 5, 2018
    26
    Scotland
    Full Name:
    William
    No, no work had been carried out prior
     
  17. yelcab

    yelcab F1 Veteran
    Consultant

    Nov 29, 2001
    8,887
    San Carlos, CA
    Full Name:
    Mitchell Le
    So you checked out the battery and alternator, good. Now check the fuel pressure at the fuel filters and at the injector rails.
     
  18. steved033

    steved033 Formula 3
    Silver Subscribed Owner

    Apr 12, 2017
    1,441
    Atlanta, GA
    Full Name:
    Steve D.
    has a tensioner gone bad and the timing belt skipped a tooth?

    the only way I could even possibly think to check this is to pull the valve covers off and see if the assembly marks are close to the rightplace..


    sjd
     
  19. tbakowsky

    tbakowsky F1 World Champ
    Professional Ferrari Technician Consultant

    Sep 18, 2002
    14,179
    The Cold North
    Full Name:
    Tom
    You have lost a bank of cylinders. Just because you have spark..does not mean you have fuel going to the injectors. The cat ecu will chop fuel, not spark.

    Start the car, and pull an ignition wire from one side of the engine. If you pull one from the running side, she will stall. Not so on the side that is not running.

    If found one bank is dead..start swapping components from side to side until the effected bank come back to life.
     
  20. Will348

    Will348 Rookie

    Dec 5, 2018
    26
    Scotland
    Full Name:
    William
    Thanks all for your suggestions, noted.

    The moment the power went, there was no sudden bang/noise or anything that made me think what the hell, just literally had the power zap away, i was turning at a set of traffic lights so low speed/ low rpm when it happended, there was a slight hesitation about 4 miles beforehand under acceleration ( not hard acceleration) which lasted a split second.

    i cant recall if the electrical gremlins happened at the exact same time although they werent present at the start of the journey and have been ever since, in talking headlight issues and half the dash wouldnt illiminate . A short was found which fixed the dash lights. My mechanic is under the impression the issue with the engine is an electrical one
     
  21. Will348

    Will348 Rookie

    Dec 5, 2018
    26
    Scotland
    Full Name:
    William
    I’m ordering a compression testing kit with comes with the following thread sizes

    M10 x 1.0 mm
    M12 x 1.25 mm
    M14 x 1.25 mm
    M18 x 1.5mm


    Can anyone confirm if any of these are the correct size or if not what thread size I need?
     
    yelcab likes this.
  22. Ak Jim

    Ak Jim F1 Rookie
    Rossa Subscribed Owner

    Dec 23, 2007
    4,247
    North Pole AK
    You can get one of those infared temperature guns fairly cheep. Could easily tell if there was a cold side to the engine. I'm no expert but based on the headlight gremlins I would look at, inspect, and clean all of the grounds in the car. Do you have a wiring diagram? Spend some time looking at it. See where the grounds are, also see if certain parts of the engine management and headlights share a common power supply/component.
     
  23. davebdave

    davebdave Formula 3
    Silver Subscribed Owner

    Mar 18, 2007
    2,357
    Northern VA
    Full Name:
    Dave W
    #23 davebdave, Dec 20, 2018
    Last edited: Dec 20, 2018
    I've had this problem twice in 10 years. Both times it was an O2 sensor.

    Edit: with the bad O2 the car started perfectly, idled ok, but no power.

    Other sensors I've replaced:
    Car hard to start, but ran well after warming up = coolant sensors

    Car difficult to start but ran perfectly after it started = cam position sensor

    Car hard to start and ran like crap = crank position sensors
     
  24. porphy

    porphy Formula 3
    Silver Subscribed

    Dec 9, 2009
    1,159
    LouisvilleKY/Switzld
    Full Name:
    Randall Gatz
    I speculate that you have partially blocked fuel filters from disintegrating rubber cushions around the fuel pumps.
     
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  25. rob.kruiswijk

    rob.kruiswijk Karting

    Jun 15, 2014
    62
    Netherlands
    Full Name:
    Rob
    I own a F348 for over 16 years, my recommendation:
    As a starter measure/verify with a multimater the following:
    - Battery voltage should be around 12V engine not running
    With engine running:
    - Battery voltage should be higher than 12V and 14.5V max
    - Headlights voltages can be easily measured at the left and right bulb fuses with main/dipped beams switched on (luggage compartment fuse box, fuse 1, 2, 11,12) measured voltage should be very close to the actual battery voltage when beams are on. (see workshop manual)
    - The "Step Pad Fuse Box" is more important, measure voltages (with heated rear switch on) on fuse number 8, 14, 18, 19 and 22
    - Make notes of every voltage for each fuse)

    >> for example if motormanagement/sensor or fuel pump voltage is too low the engine will run and rev but not produce power,
    1) due to low voltage issues with motor management sensors, the motor management receives incorrect information and provide incorrect open/close fuel injector timing.
    -2) due to low voltage the fuel pump don't produce enough fuel pressure.
    Hence no extra fuel can be provided to deliver extra power.

    Next:
    - Please start to study from C24 (operating principle) in the 348 workshop manual to make yourself familliar with the startup procedure, motormanagement and sensors. (as mentioned t1, t2, and t3 sensors)
    - Check Grounding on different sensors electrical points (see electrical schematics workshop manual)
    - look for +12V voltage points in the electric schematics (see workshop manual), particular around motormanagement components
    - Verify (the positive +12) voltages on different electrical pins on motor management and sensor components

    My best guess , you have a voltage problem in both (left/right bank) motor management systems/sensors fuel-pump related to a failure in the "Step Pad Fuse Box" of grounding problem.

    Rob
     

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