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Engine not idling

Discussion in 'Boxers/TR/M' started by Guss23, Mar 19, 2021.

  1. Guss23

    Guss23 Karting

    Jun 11, 2017
    76
    Indianapolis
    Full Name:
    Jason Sharkey
    I have my 86TR out tonight. Just got it and it’s been sitting for 3 years. Topped it off with some fresh gas and drove it for about 15 or 16 miles. While driving home as I accelerated through 4500 RPM it started surging and cutting out. I figured it was probably bad gas and tried to push through. When I took my foot off the Excelerator the engine died. Now, if I have my foot lightly on the gas it will stay running but it won’t idle. Seems to run perfectly with a little bit of throttle but not at all without
     
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  3. ChipG

    ChipG Formula 3

    May 26, 2011
    1,267
    Santa Monica, CA
    I had a similar issue back in the day, I did have spark for all 12 cylynders, my prob was from old gas (car had sat for a few years), and the gum / debris in the tank clogged up the injectors, I was able to fix it by adding about 4 cans of injector cleaner to a tank that was less than 1/4 full, it took about 20 miles of hard driving to finally clean them out.
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    20,290
    Texas
    Full Name:
    Steve Magnusson
    Are you saying that it runs smoothly when you apply a little bit of throttle, or rather roughly?
     
  5. Guss23

    Guss23 Karting

    Jun 11, 2017
    76
    Indianapolis
    Full Name:
    Jason Sharkey
    Runs smooth when applying a bit of throttle.
     
  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    20,290
    Texas
    Full Name:
    Steve Magnusson
    #5 Steve Magnusson, Mar 20, 2021
    Last edited: Mar 20, 2021
    Then first diagnostic steps IMO are:

    1. Put a timing light, or spark tester, on a spark plug wire of each bank (when you've got the engine running) to confirm/deny if spark is reaching the plugs in each bank.

    2. Inspect the fuel pump connections in the horizontal white connectors of the fuse-relay panel -- see post #6 in this thread for where to look (the connector needs to be unplugged to see the damage, if present):

    https://www.ferrarichat.com/forum/threads/left-bank-not-firing-on-testaroosa.637693

    The functional test for each fuel pump (with everything plugged in), is to remove the fuel pump relays and use a jumper wire to connect the female 30 terminal in the relay socket to the 87 terminal in the relay socket (key "off") -- you should hear the corresponding fuel pump "hum" if it is working:

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    Good Hunting!
     
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  8. Guss23

    Guss23 Karting

    Jun 11, 2017
    76
    Indianapolis
    Full Name:
    Jason Sharkey
    Looks like it’s the right hand fuel pump! Thanks for the help!! Now, How do I change the fuel pump!?
     
  9. Guss23

    Guss23 Karting

    Jun 11, 2017
    76
    Indianapolis
    Full Name:
    Jason Sharkey
    Is there a difference in the fuel pumps between 86 and 87 TR?
     
  10. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    20,290
    Texas
    Full Name:
    Steve Magnusson
    No. It's a Bosch 69532. If needed, it can be bought on Amazon for ~$160. (I've noted some F part suppliers are using a smaller, incorrect substitute.)

    How did you determine this conclusion?

    PS Be warned that the relay marked "R.H. fuel pump" operates the fuel pump mounted on the RH side of the chassis, but it serves the LH 7-12 bank. Likewise, the relay marked "L.H. fuel pump" operates the fuel pump mounted on the LH side of the chassis, but it serves the RH 1-6 bank.
     
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  11. Guss23

    Guss23 Karting

    Jun 11, 2017
    76
    Indianapolis
    Full Name:
    Jason Sharkey
    When I jumped that relay it did nothing. Thanks
     
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  13. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    20,290
    Texas
    Full Name:
    Steve Magnusson
    If the connection in the y white connector is "burned up", this will prevent the fuel pump from working when using the jumper in the relay socket -- did you inspect those connections, too?

    All you know now is that one of the fuel pumps is not working -- you need to determine WHY that fuel pump is not working BEFORE buying a new fuel pump.
     
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  14. Guss23

    Guss23 Karting

    Jun 11, 2017
    76
    Indianapolis
    Full Name:
    Jason Sharkey
    The plugs on the y cable were perfect. I think the pump simply failed
     
  15. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    6,723
    southwest germany
    Full Name:
    romano schwabel
    before you change the pump check directly at the pump with an external batterie if this will run or not. may be you have somewhere bad contact?
     
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  16. Guss23

    Guss23 Karting

    Jun 11, 2017
    76
    Indianapolis
    Full Name:
    Jason Sharkey
    Where else could there be a bad connection?
     
  17. Guss23

    Guss23 Karting

    Jun 11, 2017
    76
    Indianapolis
    Full Name:
    Jason Sharkey
    Hooked up the pump directly to the battery. It ran but sounded terrible, like there was gravel in it. I think that is the problem
     
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  18. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    20,290
    Texas
    Full Name:
    Steve Magnusson
    Now that's a test result that I can agree justifies buying a new fuel pump ;).
     
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  19. Guss23

    Guss23 Karting

    Jun 11, 2017
    76
    Indianapolis
    Full Name:
    Jason Sharkey
    Thanks guys! Can’t tell you how much I appreciate it!!
     
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