550 fuel pump/tubi interference?! | FerrariChat
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550 fuel pump/tubi interference?!

Discussion in '456/550/575' started by Poldi, Jan 13, 2008.

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  1. Poldi

    Poldi Rookie

    Nov 4, 2007
    2
    #1 Poldi, Jan 13, 2008
    The other weekend I had a tubi exhaust installed on my 2000 F550 and all seemed fine on my trip home. this weekend I returned to my mechanic to have the left muffler slightly adjusted so it would be more symmetric with the right side. The car went up on a lift and the adjustment was done. Right after starting the car again I realized a slightly different sound and a big power loss!
    Suddenly my left 6 cylinders were not firing anymore and my mechanic told me the fuel pump seemed to work not properly. After pushing on the fuel release valve on top of the left cylinder bank a little pressure and fuel came out...I started it up and all twelve were firing again and all seemed fine driving home. No luck this morning though when I started it up again..only the right side was running...
    Is it pure coincidence that after adjusting the left tubi muffler slightly that my left 6 cylinders suddenly would not fire anymore??!!! or is there a more explanation logical explanation?

    any input much appreciated.

    cheers
     
  2. cmparrenzo

    cmparrenzo F1 Rookie

    Mar 3, 2002
    2,687
    Kansas
    Full Name:
    Chris Parr
    #2 cmparrenzo, Jan 14, 2008

    You have a clogged fuel pump. This happens on 550's and other period Ferrari's. The fuel pump isolater inside the fuel pump looks like a honeycomb and it isolates the pump from the tank so you do not get the noise of the pump. the isolater is made of rubber that has a very limited life span, as it deteriorates the rubber particles are sucked into the pump. You need to replace both isolaters and most likely both pumps.

    The pumps can be taken out without removing the fuel tank from the car but all fuel has to be drained.

    This is a common issue on 550's, 575's and 360's....

    Your Tubi exhaust is not related to this issue.
     
  3. dersark_painclinic

    dersark_painclinic Formula Junior

    Mar 8, 2005
    981
    Glendale, CA
    Full Name:
    Lazik Der Sarkissian
    #3 dersark_painclinic, Jan 14, 2008
    Where is the isolater located, it is inside the pump or inside the fuel tank. what the isolater dose. Thanks
     
  4. cmparrenzo

    cmparrenzo F1 Rookie

    Mar 3, 2002
    2,687
    Kansas
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    Chris Parr
    #4 cmparrenzo, Jan 14, 2008
    The isolater is in the fuel tank, it holds the fuel pump which is surrounded by fuel....
     
  5. Poldi

    Poldi Rookie

    Nov 4, 2007
    2
    #5 Poldi, Jan 14, 2008
    Thanks for your feedback.
    I have a little over 5K miles on the car so the rubber deterioration is really caused by time rather then use. If I understood you correctly I should expect the other side to fail as well soon...
    I didn't believe the tubi had anything directly to do with it but it just seemed like such a strange coincidence that right after coming off the lift only half of the engine would work. Something (the rubber?!) must have gotten loose while up there?!
    If I have the problem you mentioned then the higher vibration/resonance of the Tubi probably accelerated the rubber deterioration.
     
  6. cmparrenzo

    cmparrenzo F1 Rookie

    Mar 3, 2002
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    Chris Parr
    #6 cmparrenzo, Jan 14, 2008
    It is time related, your Tubi was an innocent bystander!

    Replace both at the same time, the parts are cheap but the labor will make you want to do them at the same time.... good luck!
     
  7. markbnj

    markbnj Karting

    Feb 25, 2007
    62
    Central New Jersey
    #7 markbnj, Jan 14, 2008
    My 2000 550 runs rough for a couple of minutes each time I fill the tank. It runs fine until I fill up again. Do you suppose I have the same, intermittant, clogging problem?
     
  8. cmparrenzo

    cmparrenzo F1 Rookie

    Mar 3, 2002
    2,687
    Kansas
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    Chris Parr
    #8 cmparrenzo, Jan 15, 2008
    It could be, filling the tank agitates the loose rubber. On my car, filling the tank actually cleared away the particles long enough to get me home, I was filling up every 40-50 miles.
     

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