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Losing cylinders 1-6

Discussion in 'Technical Q&A' started by sabrefan, Oct 12, 2010.

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  1. sabrefan

    sabrefan Rookie

    Oct 12, 2010
    2
    #1 sabrefan, Oct 12, 2010
    Hi All, A friend of mine asked me to take a look at his '92 512 TR. After setting for about 3 months, he started in 512 up and took it for a short ride it began to run rough and finally quit. The check engine light came on and indicated a problem with cylinders 1-6. Any one have any thoughts. He seemed to think maybe one of the fuel pumps quit. Does one pump run one bank and the other take care of the other one? I would appreciate any help. Kenny
     
  2. 335s

    335s Formula Junior

    Jan 17, 2007
    870
    SF Bay Area
    Full Name:
    T. Monma
    #2 335s, Oct 12, 2010
    Logic circuit in 32 pin eprom chip for ecu on that side...
    It won't "throw" a ground in the ecu if it "thinks" that the car isnt running... thereforte, reluctors are the primary sensors for the injector and fuel pump grounding circuits..
    That said, the reluctors which are located ont the front crank timing cog and the cam position sensor MUST be functioning, or, the ecu will not recognize that gthe engine is turning over, thus, grounds will not be thrown, hence...no fuel, no spark, no fire...
    chec k the connectors at the crank, failures of the cam position sensors are also a common failure item.
    This diagnostic is usually done with my SD-1, there are other more strenuous diagnostic venues, but I have ther tool so I am n ot familiar with alternatives..
    This would be my first process of guessing-based on numerous, pr,or, experiences(30-50 caRS?)

    Let us knoiw the solution...
     
  3. sabrefan

    sabrefan Rookie

    Oct 12, 2010
    2
    #3 sabrefan, Oct 14, 2010
    I finally got around to look at that 512. Thanks for your input. The car does run but only on 6 cylinders. After doing a little testing I found that the right bank is not getting fuel. Plenty of spark but no fuel pressure at the rail. I'm thinking fuel pump, relay or fuse. Can anyone tell me where the fuel pump fuses and relays are. I couldn't find any fuse block or panel anywhere. Course I'm not used to looking at Ferraris. My XJ12 Jag has no less than 7 fuse panels! All over the car. The owner doesnt have a manual so without removing every carpet or panel in the car I figured I'd ask you guys. Thanks
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,932
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #4 Steve Magnusson, Oct 14, 2010
  5. 335s

    335s Formula Junior

    Jan 17, 2007
    870
    SF Bay Area
    Full Name:
    T. Monma
    #5 335s, Oct 21, 2010
    if the relay is not getting thrown by the ECU, then the reluctor driving that circuit is out, if the signal is feeding the relay, THEN the relay gets replaced...
    if the signal exists, AND the relay is being thrown, then the pump is faulty...
    pretty basic diagnostics, just think cause and effect....sensors and drivers, not too complicated, just a process...
     

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