1987 328 Fuel Pump Electrical Issue | FerrariChat

1987 328 Fuel Pump Electrical Issue

Discussion in '308/328' started by jdorajr, Jul 11, 2021.

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  1. jdorajr

    jdorajr Rookie

    Jun 20, 2021
    Full Name:
    Jim Dora, Jr.
    Good day.

    Went to start the 328 and no joy. Have confirmed the following.

    No power to the fuel pump

    Have confirmed fuse is good as is the relay

    Have confirmed that the pump will run with a bypass line run from the battery to the positive.

    Need help in figuring what next to check in the electrical in the car. Any thoughts are appreciated and thank you in advance for your time!
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    There are actually two relays involved in running the 328 fuel pump -- one ...113 relay understandably called the "fuel pump relay" and another less obvious ...101 relay called the "fuel injection delivery pump starting-relay" or something like that. However, the best way to diagnose the problem IMO is to remove the ...113 fuel pump relay and use a jumper wire to connect the female 30 terminal in the relay socket to the female 87 terminal in the relay socket = the fuel pump should run even with the key "off":

    Image Unavailable, Please Login

    If it does run, (replace the ...113 fuel pump relay and) try another ...101 relay in the ""fuel injection delivery pump starting-relay" position.

    If it doesn't run, measure the voltage from the female 30 metal terminal to ground and the female 87 terminal to ground = one of them should be +12V. If one does measure +12V relative to ground, but the fuel pump does not run with the 30-to-87 jumper in place, check the connector shown in post #13 in this thread for burning/frazzling:


    Good Hunting!
  3. ginoBBi512

    ginoBBi512 F1 Rookie
    Rossa Subscribed

    Oct 9, 2016
    SO CAL
    Full Name:
    I agree with all of the above, with that being said, you might want to think about having the fuse board rebuilt, I had to rebuild mine, and all electrical gremlins disappeared, it started with the fuel pump , same as you. Good luck.

    Thank you
  4. mike996

    mike996 F1 Veteran

    Jun 14, 2008
    Full Name:
    Mike 996
    I have never heard of general issues with 328 fuse/relay boards but, of course, anything is possible, especially if a PO modified/added electrical items...;)
  5. theunissenguido

    theunissenguido Formula 3
    Owner Silver Subscribed

    Jan 21, 2004
    Full Name:
    328 has the same fuseboard as mondial QV, 3.2 and t. All those cars from 25 to 38 years have problems with the plastic layers in the fusebox. Boards have the same lay out as TR, 400i, 412, F40, 288GTO but an other internal diagram. So all those cars are suffering the same heating problems, internal corrosion, loose connectors, burned connectors. Sooner or later they have to be replaced....
  6. jdorajr

    jdorajr Rookie

    Jun 20, 2021
    Full Name:
    Jim Dora, Jr.
    Good evening everyone,

    Many responded and I appreciate the help. Two people gave me links to chase down the wiring and the issue ended up being in one of the two plugs in the passenger side footwell. It is the left plug. The fuel pump is the heavy gauge mauve or very light purple. Pulled the plug apart, cleaned the contacts and put dielectric grease on it. Plugged it back together and the car runs great. Took it to the shop to have the timing belts changed and asked them to double check the plug and wiring so the car is reliable for driving!

    Thanks again everyone for your help.

    Cheers and happy motoring!!!
    waymar likes this.

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