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Technical Holley Issues (drain down)

Discussion in 'Traditional Hot Rods' started by Beep, Dec 6, 2017.

  1. I have a 57 T-Bird with a 4150 Holley 4 brl carb. This is the same carb that was on it new. It has started this issue about 5 moths after overhauling the carb. It starts great, has good throttle response and runs nice and smooth. Just like it always did. The issue: after sitting for lets say 2 to 3 days, at takes a good while to start because the fuel in the carb has drained out. IE the carb is dry. It does not leak on the outside so I assume it is draining into the engine. I thought maybe the power valve, but a new one did not fix the issue. Any ideas?

    Thanks
    Beep
     
  2. deathrowdave
    Joined: May 27, 2014
    Posts: 2,830

    deathrowdave
    ALLIANCE MEMBER
    from NKy

    I suspect the Power Valve is blown . It will allow fuel bowl to empty into the intake . Easy way to check it is , idle mixture screws adjustment , if no change when adjusting the screws , power Valve is out to lunch


    Sent from my iPhone using H.A.M.B.
     
    mad mikey likes this.
  3. Kinda what I thought. I replaced it with no results. But,,,,,it was a China one sooooooooo
     
  4. sdluck
    Joined: Sep 19, 2006
    Posts: 2,883

    sdluck
    Member

    I suspect you have a bad float and or needle and seat,easy to fix.Lots of info on this.
     

  5. Truck64
    Joined: Oct 18, 2015
    Posts: 5,316

    Truck64
    Member
    from Ioway

    Are you certain the fuel is draining or evaporating from the bowl, have you confirmed that?
     
    egads, mad mikey and joel like this.
  6. southcross2631
    Joined: Jan 20, 2013
    Posts: 4,414

    southcross2631
    Member

    I had a 57 Fairlane that did the same thing. I put a wooden spacer under the carb, replaced the float, changed the power valve, replaced the needle and seat. Bought a new replacement Holley. Problem cured. I had that old carb apart about a half dozen times.
    Try filling it up and setting it on the bench level and see if it drains setting there.
     
    mad mikey likes this.
  7. sdluck
    Joined: Sep 19, 2006
    Posts: 2,883

    sdluck
    Member

    There are 2 different gasket for the power valves.
     
  8. 97
    Joined: May 18, 2005
    Posts: 1,974

    97
    Member

    Does that carb have the lever operated bowl vents, If so it could be that the vent is open when the car is parked . Modern fuel evaporates much faster than 50s fuel this style of carb was designed for, it is formulated for sealed systems ..i.e.fuel injection. Heat from the engine will percolate fuel and leave the bowl empty if it is not running .
     
  9. Allmotor
    Joined: Jan 7, 2007
    Posts: 133

    Allmotor
    Member

    This seems to be a common problem with today's fuel.
     
  10. I could be wrong but even if the power valve leaks or is missing doesn't the fuel have to flow up to the discharge nozzle to leave the carb? this is above the fuel level so that would not drain the float bowl. I bet it is just what 97 said.
    Could be wrong.
     
    seb fontana likes this.
  11. 37gas
    Joined: May 25, 2013
    Posts: 104

    37gas
    Member

    I have the same problem on several cars, I have to many to keep all of them running . I put a cheep electric in line fuel pump with a spring loaded toggle switch so when I get in a car that I haven't driven for a while I just charge the line and carb and your good to go. Its also like carrying a spare fuel pump
     
  12. As was stated, bench test for a leak. If no leak is found, I would suspect evaporation . This fuel of today evaporates very very quickly.
     
    Dave Mc, egads and squirrel like this.
  13. oj
    Joined: Jul 27, 2008
    Posts: 6,312

    oj
    Member

    The 4150 has 1 power valve per 2 bowls, even if the PV has gone bad in the front bowl the rear bowl & accelerator pump should still work - no provision for PV back there (although some do have a 2nd PV). Let it sit for a few days, remove the air cleaner and cycle the throttle while looking down into it to see if either squirter is working, that will tell you what to do next and what needs to be fixed.
     
  14. caton462
    Joined: Jul 17, 2013
    Posts: 176

    caton462
    Member

    How is this issue going?
     
  15. squirrel
    Joined: Sep 23, 2004
    Posts: 50,929

    squirrel
    Member

    last I checked, modern fuel still evaporates quickly.
     
  16. RmK57
    Joined: Dec 31, 2008
    Posts: 2,134

    RmK57
    Member

    Bingo!

    Thats the reason quite few carbureted rods use a small electric pump to prime before start up.
     
  17. Mike VV
    Joined: Sep 28, 2010
    Posts: 2,581

    Mike VV
    Member
    from SoCal

    Simple, and has been said...

    IT'S TODAY'S FUEL...
    Install an electric fuel pump, let it run a few seconds before turning the ignition key...all will be well..!

    The alcohol component in todays fuel evaporates much more quickly than pure gasoline, and that takes much of the gas with it.

    Mike
     
  18. Truck64
    Joined: Oct 18, 2015
    Posts: 5,316

    Truck64
    Member
    from Ioway

    It's got to be the fuel itself, the "light ends"? I was convinced carb bowl was bone dry as after several days sitting the engine would need fairly long cranking to light off. Maybe 10 seconds or so. Just like the OP says.

    So instead of that, I'll pour a tablespoon of fuel down carb throat and it will then light off instantly no matter how long it has sat. Imagine my surprise though when removing the airhorn shows the fuel bowl with plenty of fuel, even after a month of sitting. Lots of complaints about this "feature" from Autolite/Holley users.

    What I should try maybe, is siphon some of the fuel that remains in the fuel bowl after sitting, and see if it has any zip left in it, by pouring that down the carb throat. I discovered that it will light off first time everytime with about 20 pumps or so, this shouldn't be necessary. It is weird.
     
    VANDENPLAS likes this.
  19. Deuces
    Joined: Nov 3, 2009
    Posts: 21,955

    Deuces
    Member
    from Michigan

    20 pumps????? Damn!:confused::rolleyes:
    If the bowl is full, it should only take one pump shot to the floor to set the choke.....
     
    Last edited: Oct 5, 2021
    egads likes this.
  20. brigrat
    Joined: Nov 9, 2007
    Posts: 5,496

    brigrat
    Member
    from Wa.St.

    Same symptom's , but guess I was stupid to think it was syphoning back to mechanical pump & tank. Put a fuel filter on it with a one way baffle and problem solved. Maybe I had diff. problem & maybe that was before the modern gas................................
    So what your saying is you can fill a glass full of modern gas, sit it on the counter and 3 day's later it will be empty or close to it?
     
  21. Truck64
    Joined: Oct 18, 2015
    Posts: 5,316

    Truck64
    Member
    from Ioway

    I know what it "should" do, and it operates perfectly otherwise except, after sitting for several days. It is really strange. This is also apparently a common problem, after searching different forum archives looking for remedies lots of folks observe the same..
     
  22. old.hot.rodder
    Joined: Oct 13, 2012
    Posts: 270

    old.hot.rodder
    Member

    I Also believe it evaporates much faster than years past. I also believe with the ethanol in the gas at engine shut off and hot heat rising from engine, the fuel rises in bowls till engine cools. This might cause some fuel to drain in the engine through the jets till the fuel cools. Then it is quite a bit lower in the bowl for two reasons.
     
  23. brigrat
    Joined: Nov 9, 2007
    Posts: 5,496

    brigrat
    Member
    from Wa.St.

    It evaporates twice as fast with dual 4's!
     
    jimmy six likes this.
  24. If you truly believe the fuel is draining down into the engine, check to make sure that your oil level doesn't read over-full. Also take a whiff of the crankcase and see if you detect a distinctly gasoline smell.
     
    tommyd and CaliforniaDreaming like this.
  25. A thread back from the dead. That makes it a "classic". You got'ta love 'em. Here's my 2 pence.......
    The fuel in my bowl was disappearing, too. On the advice of my betters, here, I bought the inline, temporary on, electric, booster pump (which I haven't spliced in yet) and I also got one of these squeeze 'primer bottles'. My fuel line must be good at keeping a full column of gas because it only takes a teaspoon dribbled in the carb to instantly start and run.
    I currently have E-10% in the gas can that I use for my mower so that's what's in the squeezer. This gives me the opportunity to observe the one or two ounces of fuel in the 'bottle' and I've noticed that it does thicken over time. Not good.
    Chapter 2 in my saga is...... I am fortunate to have 2 new gas stations in town in the last year that sell E-0, pure gas. (I think it's 90 octane, but don't quote me 'til I check.) The E-0 is what's in my '50 Chevy truck. It seems to have helped with the quicker-than-before starts, also.
    I plan to fill my lawnmower fuel can with the E-0 next time I top off the truck tank. Lawnmowers need a little love once in a while, too.

    DSCN2362.JPG
     
    Deuces likes this.
  26. old.hot.rodder
    Joined: Oct 13, 2012
    Posts: 270

    old.hot.rodder
    Member

    I am running a Holley "950" and it evaporates pretty fast too !
     
  27. jimmy six
    Joined: Mar 21, 2006
    Posts: 10,998

    jimmy six
    ALLIANCE MEMBER

    After installing 3/8” phenolic spacers under my WCFB dual quads will last at least 3 weeks. They are progressive and take a full single pump to start. I do have manifold crossover heat but it is restricted.
     
    Deuces likes this.
  28. lippy
    Joined: Sep 27, 2006
    Posts: 6,112

    lippy
    Member
    from Ks

    You can't expect it to last from 2018. :D
     

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