Control Pressure Regulator aka Warm Up Regulator Weeping Fuel | FerrariChat

Control Pressure Regulator aka Warm Up Regulator Weeping Fuel

Discussion in 'Mondial' started by Subito Grigio, Feb 19, 2018.

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  1. Subito Grigio

    Subito Grigio Formula Junior

    Jun 2, 2009
    338
    #1 Subito Grigio, Feb 19, 2018
    Be aware: My regulator has been weeping slightly for some time -- the key point here is - gasoline evaporates quickly - I never saw the leak until I happened to look at the little rubber mount bushing UNDER the CPR/WUR.

    I tightened both top banjo fittings (which were already tight) and weeping continued; so I tightened them again and weeping stopped completely.

    Unplugged safety switch and ran fuel pump each time. No more leaks. This review of fuel lines regularly is probably a very good idea to ensure there are no leaks - again, because small leaks will not be discovered due to evaporation.

    I hope that weep correction hasn't changed any pressure settings.

    J


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  2. Subito Grigio

    Subito Grigio Formula Junior

    Jun 2, 2009
    338
    #2 Subito Grigio, Feb 19, 2018
    Just took a 45 min, stop and go "errand" Drive. Two things are different I think: cold idle at 800 instead of 1000, but idles at 1,000 when warm; restart from hot is easier with less hesitation.

    My gut says the slightest leak in fuel system has a large impact on hot start, and when such a leak is combined with any of the other SIXTEEN factors that might affect hot start - we have the nightmare scenario.

    J


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  3. Subito Grigio

    Subito Grigio Formula Junior

    Jun 2, 2009
    338
    #3 Subito Grigio, Feb 19, 2018
    So - what are the other potential hot start issues mentioned in FChat and elsewhere?

    Accumulator
    Two fuel pump relays (start and run)
    Check valve failure
    Too much pedal used during hot start
    Air flow sensor
    Leaking injector valves
    Control pressure regulator/WUR
    Gas in plenum from cold start injector when hot
    Fuel pump fuse holder
    Fuse box
    Big brass knob setting
    Fuel pump running at wrong time
    Airflow metering plate connection or position
    One-way valve on fuel pump fails
    Bad Thermo-Time switch

    J


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  4. jkstevens2

    jkstevens2 Formula Junior

    Aug 25, 2015
    278
    Winter Park, FL
    Full Name:
    JK Stevens
    #4 jkstevens2, Feb 20, 2018
    Boy that's a lot of hunting. I have an ongoing hot start problem. After the car has been sitting for 30 - 40 mins from normal running temp it experiences a slow, poor ignition start. Wants to go but feels like its not getting gas. Starts to turn over then sputters and dies. I suspect fuel pump is weak and I am getting ready to replace it but your honey do list is pretty involved.
     
  5. Subito Grigio

    Subito Grigio Formula Junior

    Jun 2, 2009
    338
    #5 Subito Grigio, Feb 20, 2018
    You will probably hear from others - and as a collective group response - the primary culprits are reported to be: Accumulator, Fusebox, fuel pump.

    My comments are trying to add a focus on the fuel line banjo connectors - there are at least 15 of them visible on top of engine compartment! If any ONE of them has the slightest leak (probably can't be readily seen) the hot start problem is initiated.

    Good Luck, be safe. J


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  6. Subito Grigio

    Subito Grigio Formula Junior

    Jun 2, 2009
    338
    #6 Subito Grigio, Feb 20, 2018
    What also becomes apparent with these older cars - two or three conditions affecting hot start are in play at same time - which becomes maddening and plays with our heads.

    Also, when the hot start is known to be possible it is very important to have the battery fully charged BEFORE taking the car out!

    "I just know it's going to finally start any minute now... oh crap, the battery just died...."

    J


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  7. MvT

    MvT F1 Rookie

    May 25, 2013
    4,248
    The Netherlands - NH
    Full Name:
    Tijn
    #7 MvT, Feb 21, 2018
    You named it all. Like you said the hot start is usually a multiple issue thing. I'm in the opinion one need to overhaul/check the K jetronic and the you are covered. From factory the lever is adjusted properly, leaving the wear aside, and you would not have to fiddle around with the adjustment screw if you manage to correct all leaking stuff.

    Injectors are the parts that most subject to wear. Replacing them and you will sometimes have a totally different ride. Testing them is a waste of money as they are 30 euro (40 USD) a piece.
     
  8. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,145
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #8 Steve Magnusson, Feb 21, 2018
    Add "O-rings inside the pressure regulator section of the fuel distributor leaking (for K-Jet)" and "Pressure Regulator leaking internally (for KE-Jet)" -- but these, and many of the other items in your list can be ruled in, or out, by just measuring the regulated supply pressure after shutoff (i.e., if having a warm restart problem, measuring the regulated fuel pressure after shutoff should be done before replacing any components - JMO).
     
  9. spicedriver

    spicedriver F1 Rookie

    Feb 1, 2011
    3,859
    #9 spicedriver, Feb 21, 2018
    Odd that the WUR fittings would just start leaking, unless they were removed recently. Also note the crush washers should be replaced every time the fittings are to be tightened.
     
  10. Subito Grigio

    Subito Grigio Formula Junior

    Jun 2, 2009
    338
    #10 Subito Grigio, Feb 22, 2018
    Note of strong caution: banjo fittings, I believe, should only be tightened IF weeping is discovered. Please don't fool around with banjos. In worst case We are talking raw gasoline SPRAYING on a still hot catalytic converter. I'm only suggesting cold engine tightening IF weeping is discovered. Also, an incandescent bulb anywhere near banjos is dangerous.

    Find an expert to work on your fuel system! J


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