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Fuel pumps unusual noise and no start

Discussion in 'Boxers/TR/M' started by N17RO, Jan 13, 2021.

  1. N17RO

    N17RO Karting

    Apr 9, 2013
    182
    UAE
    Full Name:
    Craig
    Hi all,

    Car was running fine before being put away for about 5 months.

    Gone in to start her and go for a drive and it's making this odd noise from the fuel pumps and won't start.

    I've gone through some check already.
    - I have spark in all cylinders.
    - tested that I get +12v to the red wire on the coolant Y pipe sensor when cranking.
    - tested the fused protection relay in the black box in the passengers rear wing and all is fine there.
    - bridged the above, all ok.
    - bridged the fuel relays in the fuse panel and the noise in this video happens. One side clicks continuously the otherwise makes a thud.

    - Fuel filters, pressure regulators were all replaced about 2 years ago and seem to be fine.

    Any help would be welcomed.

    Link to video with sound
     
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  3. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    6,613
    southwest germany
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    romano schwabel
    is this sound coming from the fuel pumps? sounds very strange to me :(

    could it be that the fuel tanks are out of gas and the pumps pumping only air?
     
  4. N17RO

    N17RO Karting

    Apr 9, 2013
    182
    UAE
    Full Name:
    Craig
    I thought the same at first but the noise is coming from the area under the tank. I thought there was maybe some other relay down there but nothing I can find in the workshop manuals or on search so it really only leaves the pumps.

    It was a bit low on fuel and I've since filled it half way.
     
  5. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    19,940
    Texas
    Full Name:
    Steve Magnusson
    #4 Steve Magnusson, Jan 13, 2021
    Last edited: Jan 13, 2021
    Not good, and until the fuel pumps run normally with the jumper in place at the corresponding relay socket, it doesn't matter to worry about anything else.

    Have you inspected the fuel pump connections in the y horizontal white at the bottom of the fuse-relay panel (by unplugging it)? A large PN (beige-black) wire and a large P (beige) wire.

    Also wouldn't hurt to unplug/inspect/reseat the very large 2-spade d-e connector in the RH upper corner of the fuse-relay panel with two huge red wires that brings battery power into the fuse-relay panel and make sure things are clean and the spade connections are tight. Also, make sure the loop terminal where these red wires connect to the stud on the battery positive terminal clamp are clean/tight.

    PS Please confirm year and version TR -- is it a CH87 (1987 Swiss) or maybe SA version TR? (Doesn't make any difference for the fuel pump operation, but like to know who the patient is - and the dual air injection check valves indicate it is.)

    PPS Well done so far -- you've correctly eliminated a bunch of stuff, and found a for sure fatal flaw.
     
  6. N17RO

    N17RO Karting

    Apr 9, 2013
    182
    UAE
    Full Name:
    Craig
    Hi Steve thanks for the points above.

    I have not and will do this in the morning.


    I have already done this as in the past it was causing an issue. Both battery and the connector are clean and seated well.


    Its a European 1992. And yes not a typo :) 1992 Jan 1st registered.

    That's thanks mostly to yourself Steve. I found some very valuable threads which gave a good insight of what to test.
     
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  8. N17RO

    N17RO Karting

    Apr 9, 2013
    182
    UAE
    Full Name:
    Craig
    Hi Guys took me a while to find time to keep searching and I've found a real problem with the Y connector. The wires that Steve mentioned were missing and when I removed the connector I found it was burnt. So pre-existing issue which was never properly sorted.

    I've owned the car for 7 years so this must have been one of the two previous owners being cheap.

    So I'm currently searching for the missing wires but feel its going to be easier to get under the car and try to trace back from the pumps. Correct the fuse box issue and rewire the Y connector.


    Image Unavailable, Please Login
     
  9. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    6,613
    southwest germany
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    romano schwabel
    good that you found out the mistake, now only to fix it. may be use 2 external relais for the 2 fuel pumps
     
  10. N17RO

    N17RO Karting

    Apr 9, 2013
    182
    UAE
    Full Name:
    Craig
    Hi Joe. I found the wiring directly soldered to the fuse board. The 12v power does come through it so I'm going to do one final check at the fuel pumps before pulling the trigger on new ones.

    I did do a fuel pressure test and confirm bank 7 to 12 has very poor fuel pressure and 1 to 6 is ok.

    The car is now trying to at least start.
     

    Attached Files:

  11. EZORED

    EZORED Formula Junior
    Silver Subscribed

    Nov 24, 2007
    653
    Scottsdale, AZ
    Full Name:
    Dennis
    That looks speciously like the fix I found on my old board! Probably time to get a new one form GT Car Parts and the connector also. Will be a big improvement!
     
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  13. Veedub00

    Veedub00 F1 Rookie
    Silver Subscribed Owner

    Jun 30, 2006
    3,956
    Troy, Michigan
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    James
    I sent my board to Dave Helms at Scuderia Rampante Innovations. He also does really great work.
     
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  14. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    19,940
    Texas
    Full Name:
    Steve Magnusson
    Just FYI -- those other two wires that are directly soldered to the board by the arrow you added are for the water radiator fans. And I would have to guess that something similar has been done to the AC Power connection, too, as that is the one that usually fries first:

    Image Unavailable, Please Login

    If you do decide to buy another replacement fuse-relay panel, my preference order (and comments) are:

    1. Guido's (theunissenguido member name) -- Has large wire conductors for better heatsync behavior at the connections, replaces the horizontal female white 2-prong connector terminals with much more reliable and high-current capable spade-style terminals, leaves all the relays in their stock locations, and no wire splicing in the harness. My only minor nit is how the wire conductors are connected to the terminals as they are just soldered rather than being mechanically connected and soldered (but he's got a lot of them out there working fine for a long time).

    2. GT Car Parts -- Has thicker PCB traces for better heatsync behavior at the connections, leaves all the relays in their stock locations, and no wire splicing in the harness. Still uses the 2-prong female terminals in the horizontal white connectors AFAIK so relies on the thicker traces to prevent the terminal burning from occurring.

    3. Scuderia Rampante -- Works fine, and solves the terminal burning problem by eliminating them completely, but is the most obviously modified. Some relays and fuses moved to new location, added exposed wires, and harness wire splices needed.

    All JMOs, as any would be OK functionally -- and I favor modifications that are not noticeable so that influences my preference a lot.
     
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  15. N17RO

    N17RO Karting

    Apr 9, 2013
    182
    UAE
    Full Name:
    Craig
    Thanks for the info on the fuse panels Steve. I'm going to replace the pumps 1st then I'll replace the fuse board once she's running right again.
     
  16. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    6,613
    southwest germany
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    romano schwabel
    I not care at my competition if you see some not original, the whole car meanwhile is not original. for me the technical has to be perfect.
    but if I would have an original car I also would do so that at first sight none will see modifications.
     
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