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79 308 gtb euro loses power

Discussion in 'Technical Q&A' started by wmmr2985, Mar 7, 2014.

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  1. wmmr2985

    wmmr2985 Rookie

    Apr 23, 2012
    4
    dallas, texas
    Full Name:
    murray ross
    #1 wmmr2985, Mar 7, 2014
    My car starts up and runs fine, but after a bit it feels like it loses power to a bank of cylinders or has run out of gas and slowly dies. After a minute or two it fires right up and runs great like nothing happened. It is not the fuel pump as it is new and I can hear it running after the car dies. Have checked connections at distributor, which is an electronic setup. Any ideas appreciated.
    Will Ross
     
  2. Ferraripilot

    Ferraripilot F1 World Champ
    Owner Project Master

    May 10, 2006
    17,847
    Atlanta
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    John!
    #2 Ferraripilot, Mar 8, 2014
    What electronic setup do you have running things?
     
  3. 2NA

    2NA F1 World Champ
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    Dec 29, 2006
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    Tim Keseluk
    #3 2NA, Mar 8, 2014
    Check your fuel filter.

    Don't be quick to rule out the pump. Just because it's "new" doesn't mean it can't fail.
     
  4. wmmr2985

    wmmr2985 Rookie

    Apr 23, 2012
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    murray ross
    #4 wmmr2985, Mar 8, 2014
    It is a MSD Digiplex. About as much as I know. Could the ignition relay cause this? It is 35 years old.
     
  5. wmmr2985

    wmmr2985 Rookie

    Apr 23, 2012
    4
    dallas, texas
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    murray ross
    #5 wmmr2985, Mar 8, 2014
    If it is the pump, wouldn't it crap out completely. The fuel filter was replaced with the fuel pump. Thanks for the reply.
     
  6. 2NA

    2NA F1 World Champ
    Consultant Owner Professional Ferrari Technician

    Dec 29, 2006
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    Tim Keseluk
    #6 2NA, Mar 8, 2014
    Last edited by a moderator: Sep 7, 2017
    What you are describing sounds like a fuel starvation problem to me. It could also be the fuel inlet screen (#16)

    Test it or you won't really know.
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  7. Ferraripilot

    Ferraripilot F1 World Champ
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    May 10, 2006
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    #7 Ferraripilot, Mar 8, 2014
    Check for 4psi and plenty of volume. What kind of pump was used when it was replaced
     
  8. wmmr2985

    wmmr2985 Rookie

    Apr 23, 2012
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    dallas, texas
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    murray ross
    #8 wmmr2985, Mar 8, 2014
    The screen it the bottom of the tank, #16 was taken out and cleaned with the tanks when the car was being restored, just a couple of months ago. The fuel pump sends 34 gallon per hour, not sure of psi. It seems electrical. Does the ignition relay play any part after engaging the starter?
    Thank you for your input.
     
  9. BigTex

    BigTex Seven Time F1 World Champ
    Owner Rossa Subscribed

    Dec 6, 2002
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    Bubba
    #9 BigTex, Mar 8, 2014
    How are the MSDs fed electrically?

    Should be a #10AWG wire IIRC, I had one fed with an oversurrent relay instead of the proper fuse, and it would cut in and out as you are describing..

    Check out all of that.
     
  10. hanknum

    hanknum Formula 3

    Nov 1, 2003
    2,050
    Santa Barbara
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    Henry
    #10 hanknum, Mar 9, 2014
    Yeah, I think it is fuel related...either filter or pump.
     
  11. 2dinos

    2dinos F1 Rookie

    Jan 13, 2007
    3,023
    #11 2dinos, Mar 12, 2014
    I'm going thru something similar - I'm chasing the pump & filter and will check flow and pressure. I notice that I wait for carbs to fill, and she starts right away, but after only ~ 2 minutes, it starts to run poorly, and I notice the sound from the pump changes.

    I'd like to check tank screen, but the tank is full, so not now.

    Curious what pump you're using. I'm going to try a Pierburg. The Facet is highly recommended but they're noisy.
     

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