Holley Carb, Wanting suggestions with reoccurring flooding

Engines, Exhaust and Fuel Systems

  1. ChryslerCruiser

    ChryslerCruiser Well-Known Member

    Messages:
    96
    Likes Received:
    8
    Joined:
    Jun 27, 2019
    Location:
    Morrisville VT
    I believe this is a 4160 vac Secondary carb.

    I'n new to Holley carbs. Last summer the imperial would not run or idle well, and it turned out to be the rear float valve had crud in it, and the high fuel level was leaking into the engine.

    Got an Edelbrock carb kit locally, cleaned the fuel bowls and all is well.. ended up only using the float bowl gaskets at that time, the rest of the carb kit went on the shelf.

    Car just quit while idling, and a puddle under the secondary throttle shaft lead me to pull the carb and have a look-see. Sure enough black grit like stuff in the rear float bowl. I have had a fuel filter just in front of the carb inlet the whole time. . . It is a metal filter, so I do not know if it is catching a lot of junk or not.

    A couple of questions:

    Where can I get some "great" float bowl gaskets? The Original ones were blue, and stuck like glue to both half's of the float bowl surfaces.. The black ones just ripped on the primary side as well.. is there a better solution regarding gaskets? does soaking them in WD40 or something of the like get them to release better?

    Does the fact that it is the rear float bowl that is getting the sediment, suggest a problem within the carb? I did not think to see if the black grit was actually sand, or rubber, or what it was..

    And I just had the question pop up: the rear float bowl should not be getting much fuel, as the car is not even being driven on the road, only moved out of the shop and around the yard, to get it out of the way of what ever project is in full swing. So it would seem that the rear float bowl should have stale fuel in it by now.. any thought or suggestions welcome.
     
  2. Camtron

    Camtron Well-Known Member

    Messages:
    536
    Likes Received:
    195
    Joined:
    Apr 25, 2019
    Location:
    Here
    Wonder if you have a clogged float bowl vent from the mentioned, black grit. Could cause the fuel to back up and flood the secondaries if the pressure can’t vent.
    If you put your finger over the float level hole and fuel is feeding through the secondaries at idle, I’d feel confident about a clog.
     
  3. 80mirada

    80mirada Well-Known Member

    Messages:
    1,202
    Likes Received:
    353
    Joined:
    Sep 3, 2012
    Location:
    Wisconsin, West Bend depends
    Is the charcoal canister hooked up? Sounds like it may have failed leading to the charcoal being sucked into the carb, had this happen on an early 2.2 and it was a pain to figure out
     
  4. ChryslerCruiser

    ChryslerCruiser Well-Known Member

    Messages:
    96
    Likes Received:
    8
    Joined:
    Jun 27, 2019
    Location:
    Morrisville VT
    I will go looking for the secondary bowl vent....

    And will look at the charcoal canister, I know it is present, but not sure how it is attached to the fuel system, so I will be doing some exploring and learning here.
     
  5. Aspen500

    Aspen500 Well-Known Member

    Messages:
    5,127
    Likes Received:
    1532
    Joined:
    Feb 14, 2015
    Location:
    Rib Mountain (Wausau) WI
    The charcoal canister was my first thought also. Had it happen on my old '81 D150 and it cause no end of grief (plugged passages, stuck open needle valve) until I had a "DUH" moment and it occured to me what the black grit was. A new canister and all was well.

    The charcoal shouldn't be able to escape the canister but if the screen mesh ruptures, out it goes.

    You can pull the bowl vent hose off the canister and see if any charcoal is present in the hose.

    About the bowl gaskets, Summit has a bunch of the non-stick gaskets. You'll have to scroll through them to find the ones you need but, this is the link:
    Carburetor Fuel Bowl Gaskets
     
    Last edited: Sep 16, 2020
  6. ChryslerCruiser

    ChryslerCruiser Well-Known Member

    Messages:
    96
    Likes Received:
    8
    Joined:
    Jun 27, 2019
    Location:
    Morrisville VT
    Thinking out loud here guys....

    Please forgive my ignorance here, and understand I am not questioning the validity of this suggestion... as it makes more sense that the black grit I saw was charcoal, rather than bits of rubber from say a failing fuel line.. as I had assumed.

    AND as I have not yet started tracing the charcoal canister lines to learn how they connect with the fuel system... so it all may become clear once I get under the hood:

    But as I sit here, I am failing to connect how the canister when in failure mode, gets it's grit into the float bowl. . . Guessing it is some type of emissions valve that opens to suck vapors out of the Charcoal canister.. but my imagination puts that at the base of the carb. WAIT a minute. the vacuum advance line goes to the front bowl, and I have wondered why it has a "T", so that must be the avenue of charcoal delivery?
     
  7. ChryslerCruiser

    ChryslerCruiser Well-Known Member

    Messages:
    96
    Likes Received:
    8
    Joined:
    Jun 27, 2019
    Location:
    Morrisville VT
    No such luck.. so I guess I will flush out the carb, change to a see through fuel filter, and see if that is the issue. Will also identif/ find the carb vent, to see if that is plugged and causing the flooding.. I have discovered in this process that my spark quality is less than impressive, so the whole exercise has been a good learning experience so far.
     
  8. Aspen500

    Aspen500 Well-Known Member

    Messages:
    5,127
    Likes Received:
    1532
    Joined:
    Feb 14, 2015
    Location:
    Rib Mountain (Wausau) WI
    There are certain conditions where charcoal can be sucked up the bowl vent hose and into the bowl. It doesn't take much of a vacuum to move the particles. Not saying that's what you have happening, but it does happen. It did on my D150 anyways. I found charcoal in the bowl vent hose between the canister and carb, along with the bowl.
     
  9. ChryslerCruiser

    ChryslerCruiser Well-Known Member

    Messages:
    96
    Likes Received:
    8
    Joined:
    Jun 27, 2019
    Location:
    Morrisville VT
    The black grit must be coming from somewhere else.. as the charcoal canister is not hooked up. Once I get the carb cleaned, I will hook up the canister, with a Fuel filter in line, in the off chance that it does fail.. Guessing the previous owner unplugged it when he swapped to a carb..
     
  10. Camtron

    Camtron Well-Known Member

    Messages:
    536
    Likes Received:
    195
    Joined:
    Apr 25, 2019
    Location:
    Here
    Sorry, on the passenger (right) side of the secondary housing, is where the float level hole is. Sometimes it’s actually a glass sight so you can see the fuel level in the secondaries, but normally it’s a brass screw/bolt that you can remove to do a visual inspection of the fuel/float level in the secondaries.
    The secondary vent tube would be the tube that comes straight out of the top of the carb closet to the firewall (the one closer to the thebfront of the engine is the primary vent tube. There’s also a vent tube valve inside the secondary housing that could need cleaning.
    Holley has full diagrams of the carb online for reference.

    Do you happen to have older rubber fuel lines anywhere on the car? That could be where the black grit is coming from.
     
  11. Aspen500

    Aspen500 Well-Known Member

    Messages:
    5,127
    Likes Received:
    1532
    Joined:
    Feb 14, 2015
    Location:
    Rib Mountain (Wausau) WI
    Well then,,,,,,,,,,,never mind:D
     
  12. ChryslerCruiser

    ChryslerCruiser Well-Known Member

    Messages:
    96
    Likes Received:
    8
    Joined:
    Jun 27, 2019
    Location:
    Morrisville VT
    Thanks Camtron for the guidance in finding the Float Bowl Vent. As far as old rubber fuel lines, AFAIK I replaced them all last summer. I will check that aspect tomorrow, and dive into the carb repair as well.
     
  13. ChryslerCruiser

    ChryslerCruiser Well-Known Member

    Messages:
    96
    Likes Received:
    8
    Joined:
    Jun 27, 2019
    Location:
    Morrisville VT
    If it had been hooked up, I would Never, ever, EVER have thought that the charcoal canister would/could be sending out black grit.. With out the wisdom and experienced insight offered here. IF it doe happen in the future, well I will be ready for it!!!
     
  14. ChryslerCruiser

    ChryslerCruiser Well-Known Member

    Messages:
    96
    Likes Received:
    8
    Joined:
    Jun 27, 2019
    Location:
    Morrisville VT
    NEW Question: Can a nitrophyl float fail by way lf releasing black grit??
    No issue was found, it appears smooth, and looks ok, but I am trying to consider all possibilities...

    What I have observed:
    1) the black grit was only in the rear fuel bowl.
    2) there is a screen on the inlet barb, and it is perfectly clear.. absolutely no sediment or junk in it. so I am guessing it is not coming by way of the fuel line.

    That leaves the vacuum port, and or a failed float?
    I am headed directly to investigate the vacuum line, and to blow it out with carb cleaner into a clear glass to see what turns up.

    Also I am amazed at the endless amount of gaskets. Not a fan of the Holley carb for a street vehicle. On a RACECAR, maybe, but there are way to many options for fuel to leak past a gasket or O-ring on this carb... At least the Edelbrock carb kit I got provides rubber like gaskets for the 8 fuel bowl screws..
     
  15. Aspen500

    Aspen500 Well-Known Member

    Messages:
    5,127
    Likes Received:
    1532
    Joined:
    Feb 14, 2015
    Location:
    Rib Mountain (Wausau) WI
    I've never been a fan of carbs with gaskets below the fuel level (like some Holley's for example). Always seems like a fuel leak waiting to happen.:eek:
     
  16. ChryslerCruiser

    ChryslerCruiser Well-Known Member

    Messages:
    96
    Likes Received:
    8
    Joined:
    Jun 27, 2019
    Location:
    Morrisville VT
    Amen!! Actually this is the first Holley 4bbl I have ever had, or played with. I had always heard that they were "EASY" to tune and adjust. That may be so, but the gaskets are kinda expensive, and so far I have yet to get a fuel bowl drained into a container. Maybe, someday I will find the magic with this style carb, but I think it is going on the shelf as soon as I get a Mopar Q-jet...