Results 1 to 9 of 9
  1. #1
    Join Date
    May 2014
    Location
    Cheshire
    Posts
    38

    Carburettor - flooding?

    Hi Guys,

    I am not a technical expert, so any help would be most appreciated.

    Recently, my Cobra (AK with Ford 5.8 V8 engine) has not been running as smoothly as it has done so for the past 5 years. When I put my foot down to accelerate, the car hesitated and then lurched but not with as much power. I have had new plugs and leads fitted, this didn't work, so I have had the Carb cleaned with a "new kit" fitted (I believe this was new valves / floats?), and also a new fuel regulator.

    Anyway, after 4 unsuccessful trips to the garage, the Carburettor is flooding when I turn off the engine, it is like a fast dripping tap and I cannot re-start the engine until the dripping has stopped and any excess fuel has evaporated - this took more than an hour last weekend at the local garage forecourt.

    Would you guys please have any advice / tips / knowledge on what might be causing the carburettor to flood? (PS, it is a Webber Carb).

    Many thanks in advance.

    Andy

  2. #2
    Join Date
    Aug 2009
    Location
    Birmingham
    Posts
    579
    The return is not blocked by any chance?
    It just does....

  3. #3
    Join Date
    Apr 2004
    Location
    East Leake, Nottinghamshire, England.
    Age
    55
    Posts
    9,489
    Quote Originally Posted by Daryn Smith View Post
    The return is not blocked by any chance?
    Carbs don't usually have a return that I have ever seen ?
    Martin

    351W 416.7 HP and 466.8 ft-lbs

    Running Mega Squirt and Edis 8


  4. #4
    Join Date
    Apr 2014
    Location
    Stourport on Severn
    Age
    61
    Posts
    237
    Could be the float/needle valve isn’t seating correctly and carb is flooding when under pressure from fuel pump. Is the fuel pump electric or engine driven?
    Cheers
    Steve

    My missus asked me to build her a Cobra! – How good is that!

    AK Gen2 chassis arrived 12/2/15 IVA Passed 2/7/18 on road 29/7/18
    http://stevesakcobrabuild.blogspot.com

  5. #5
    Join Date
    May 2014
    Location
    Cheshire
    Posts
    38
    Hi Steve, the fuel pump is electric (I think).

  6. #6
    Join Date
    Jan 2006
    Location
    Chelmsford Essex
    Posts
    803
    Hi Andy

    As Steve says your float levels are to high so not closing off the needle valve.

    You should have a float bowl hight adjustment screws for front and back bowls to adjust the heights.
    Also a stuck needle float valve with dirt will give you the same problem.

    A good way to check is take off the air filter and look down both bowl barrels and turn the ignition on , no fuel should be coming from the top feed into either primary or secondary

  7. #7
    Join Date
    May 2014
    Location
    Cheshire
    Posts
    38
    Hi Jon,

    Many thanks for the advice.

    I have done as you suggested, and the bowls are filling up each time when I turn the ignition on, as well as dripping and filling up the bowls when the ignition has been turned off for maybe 10 to 15 minutes.

    The engine will then not start again until the fuel in the bowls has vaporized and the dripping had stopped.

    Andy

  8. #8
    Join Date
    Jan 2006
    Location
    Chelmsford Essex
    Posts
    803
    This is a good explanation

    https://www.youtube.com/watch?v=8LNgwZe6r9s

  9. #9
    Join Date
    Nov 2006
    Location
    Shropshire/Wales Border
    Age
    48
    Posts
    5,937
    If adjusting the float height doesn’t sort it, it could be whoever replaced the needle valve replaced the needle but not the seat and they’re not mating together properly.

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •