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308 throttle body fuel leak and starting problem

Discussion in 'Technical Q&A' started by pnorman, Jan 12, 2004.

  1. pnorman

    pnorman Rookie

    Dec 30, 2003
    47
    #1 pnorman, Jan 12, 2004
    My 308 2v will not start. It always started cold but I recently began having hot start problems. I replaced the fuel accumulator because the diaphram was leaking. It started right up and ran but now a few days later, the engine turns over but won't start. It smells flooded and fuel is dripping out the throttle body at the linkage. I've never experienced this particular problem in years of owning and maintaining exotics. I have spark and obvious fuel pressure. Everything looks in order. It was running fine until these problems began. Help!!!
     

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  2. tbakowsky

    tbakowsky F1 World Champ
    Professional Ferrari Technician Consultant

    Sep 18, 2002
    16,358
    The Cold North
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    Tom
    #2 tbakowsky, Jan 12, 2004
    Fuel dripping out of the throttle body?? Wow!! never seen that before!!

    The only thing i could see causing that would be the fuel distributor leaking around the pintel. The woud cause fuel to pool in the bottom of the airfolw sensor. When you crank the engine, engine vac will draw the fuel into the t-body. This could also explain your hard start problem. The fuel leaking out will ciause a drop in rest pressure. This can cause vapour lock and give you a hard start problem.
     
  3. pnorman

    pnorman Rookie

    Dec 30, 2003
    47
    #3 pnorman, Jan 12, 2004
    Thanks for the quick response. Is that something that can be repaired or do I need a new fuel distributor? It was an intermittent problem over the last couple of weeks but now won't start. Did the leak just get progressively worse during this period resulting in the no start. Is the pintel the plunger or the diagram in the fuel distributor?
     
  4. tbakowsky

    tbakowsky F1 World Champ
    Professional Ferrari Technician Consultant

    Sep 18, 2002
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    Tom
    #4 tbakowsky, Jan 12, 2004
    The pintel is the part that extends down into the air flow meter. This pintel conntacts the sensor plate. As negative pressure is created by the engine the plate moves down, pushing up on the pintel causeing more fuel to floww to the injectors. You can check to see if the pintel seal is leaking by removing the fuel distributor and looking at the pintel itself. If you see fuel dripping down the sides of the pintel then it is leaking. One word of caution: do not activate the fuel pumps with the fuel distributor romoved from the air flow meter. Just pressureize the system and turn off the key. Then remove the distributor form the airflow meter. No need to disconnect any lines. Just leave everything attached and lift it off. Becarful of the little o-ring around the base of the distributor.

    If you don't find a leak there then obviously more check is needed.

    HTH
    Tom
     
  5. pnorman

    pnorman Rookie

    Dec 30, 2003
    47
    #5 pnorman, Jan 13, 2004
    Well, I lifted the fuel distributor and no leakage. Plunger is moving freely as tested in the manual. No fuel in the air sensor body. The fuel seems to be coming from behind the throttle plate not from the air sensor side.
     

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  6. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
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    #6 f355spider, Jan 13, 2004
    Cold start injector running too long, and flooding???
     
  7. pnorman

    pnorman Rookie

    Dec 30, 2003
    47
    #7 pnorman, Jan 13, 2004
     
  8. 308GTS

    308GTS Formula 3

    Dec 27, 2001
    2,221
    TN
    #8 308GTS, Jan 13, 2004
    Yes the CSI should only work when it is cold out but sometimes the termo time switch sticks and causes the CSI to keep spraying. Just unplug the blue harness connector up on the right side of the plenum chamber. Maybe it will help.
     
  9. snj5

    snj5 F1 World Champ

    Feb 22, 2003
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    #9 snj5, Jan 13, 2004
    I agree with Dave that the Cold start injector may be stuck on. Unplug the wire and try to start. The injector part is common to all Kjet cars (vw, volvo) -
    Can test by taking it off and see if it contiually sprays when powered on. Could be a relay as well.
    Good luck
    rt
     

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  10. pnorman

    pnorman Rookie

    Dec 30, 2003
    47
    #10 pnorman, Jan 13, 2004
     
  11. f355spider

    f355spider F1 World Champ
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    May 29, 2001
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    #11 f355spider, Jan 13, 2004
    You need it for cold start, but not warm or hot start. You need to test it to see if it only sprays during cranking(normal), or if it keeps spraying when the ignition is in the "on" position(not normal)...

    I don't know the test procedure for this, so tread carefully with gasoline! And seek expert advice...not from a "hack" like me. :)
     
  12. snj5

    snj5 F1 World Champ

    Feb 22, 2003
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    #12 snj5, Jan 13, 2004
    The only place I know in a Ferrari Kjetronic where fuel will leak DOWN to the throttle body to drip is the cold start injector. Every other source of fuel save filling up an entire runner with fuel from a open injector) is lower than the throttle body. That's why it seems to me that that is the problem.
    Not sure what you did to test, but would be concerned that 1) it leaks while under pressure 2) is inappropriately triggered from a bad relay or cold start timer. I had a the fused relay on the ECU board go bad.

    Good luck
    rt
     
  13. pnorman

    pnorman Rookie

    Dec 30, 2003
    47
    #13 pnorman, Jan 14, 2004
     
  14. pnorman

    pnorman Rookie

    Dec 30, 2003
    47
    #14 pnorman, Jan 14, 2004
     

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