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F40 Fuel pump problem

Discussion in 'Technical Q&A' started by Bertocchi, Mar 20, 2006.

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  1. Bertocchi

    Bertocchi Formula 3
    Consultant

    Jan 28, 2004
    2,330
    Austin, Texas
    Full Name:
    David Castelhano
    #1 Bertocchi, Mar 20, 2006
    The right side fuel pump on my F40 is not energizing. The fuel pump has been removed and shipped to Kinsler and checks out fine. The relays are all OK. If I ground the appropriate pin at the ECU the fuel pump activates. I have changed ECUs from side to side, no difference. Also I have switched power modules from side to side and have had no difference.
    I believe that the ECU is not recieving a signal that would allow it to ground the the fuel pump relay? Does anyone have any suggestions on where to look next?
     
  2. Motob

    Motob Formula 3
    Professional Ferrari Technician

    Nov 11, 2003
    2,370
    Frederick, Maryland
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    Brian Brown
    #2 Motob, Mar 20, 2006
    Does the engine have spark and fuel injector function on the right side of the motor?
    If not possible causes are: RPM sensor, stroke sensor, fuel injector relay, bad ground connection (fuel injection harness to engine).

    Brian Brown
    Patrick Ottis Co.
     
  3. Bertocchi

    Bertocchi Formula 3
    Consultant

    Jan 28, 2004
    2,330
    Austin, Texas
    Full Name:
    David Castelhano
    #3 Bertocchi, Mar 20, 2006
    Everything on the right side functions correctly accept the fuel pump. If I jump the fuel pump relay the car runs fine.
     
  4. Simon^2

    Simon^2 F1 World Champ

    Oct 17, 2005
    12,313
    At Sea Level
    #4 Simon^2, Mar 20, 2006
    this will be a PITA but, try swapping the fuel pumps left/right.

    If the prob stays with the pump, it's the pump despite what the diags say. if the problem stays on the same side, it's not the pump.

    good luck. keep us updated...
     
  5. Bertocchi

    Bertocchi Formula 3
    Consultant

    Jan 28, 2004
    2,330
    Austin, Texas
    Full Name:
    David Castelhano
    #5 Bertocchi, Mar 20, 2006
    Thanks for your comment. It is not the pumps! If I ground the grey wire that goes from the right side fuel pump relay to the 36 pin connector to the ECU the fuel pump comes on and the pressure is great.
    I feel that the ECU is looking for something, possibly a sensor, to tell it it is OK to turn on the fuel pump and is not finding it or getting eronious information from it?
     
  6. Simon^2

    Simon^2 F1 World Champ

    Oct 17, 2005
    12,313
    At Sea Level
    #6 Simon^2, Mar 20, 2006
    Beyond my knowledge base. Let us know what you find.
     
  7. Motob

    Motob Formula 3
    Professional Ferrari Technician

    Nov 11, 2003
    2,370
    Frederick, Maryland
    Full Name:
    Brian Brown
    #7 Motob, Mar 21, 2006
    Typically the injection control unit will look for the crank input from the ignition switch. It will run the fuel pump during cranking. After the key is released and the engine starts it will look for the RPM/Stroke sensor inputs to see if the engine is running and then keep the fuel pump running.

    Since the engine runs on the right side, all the inputs that are necessary to run the fuel pump should be present. I haven't looked at the wiring diagram, If I get a chance tomorrow I'll take a look. But it sounds like a poor ground connection or broken ground wire.

    The injection control unit has multiple ground wires. It may be possible that the ground wire that supplies the ground to the portion of the control unit that controls fuel pump relay operation is bad. I would check all of the grounds at the control unit by performing a voltage drop test across them while cranking the engine with the fuel pump relay in its normal place. If you see any voltage at a ground connection, then you know that it is the problem.

    Brian
     
  8. Bertocchi

    Bertocchi Formula 3
    Consultant

    Jan 28, 2004
    2,330
    Austin, Texas
    Full Name:
    David Castelhano
    #8 Bertocchi, Mar 21, 2006
    I will check the grounds. Thanks!
     
  9. ROLOcr

    ROLOcr Formula Junior

    Oct 25, 2005
    619
    Costa Rica
    Full Name:
    ROLO
    #9 ROLOcr, Mar 21, 2006
    isn't the fuse and relay panel on f40's supposed to be changed every 10 years??
    this is because it gets damaged thru time, maybe the relay works BUT the cable that goes from the relay to the pump is damaged along the way, in the relay panel
    good luck
    ROLO
     

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