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Carb rebuild problems - help!

Discussion in '1965-1970 Shelby Mustang GT350 & GT500' started by malstrom, Mar 31, 2013.

  1. malstrom

    malstrom Member

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    Hello Men

    I own a 1966 Fastback. Not a Gt 350 sadly but I was hoping a group of someones might help me with my problem of trying to resurect my garage sculpture.


    The guys over at IH parts no longer respond much to my threads but here is a link to my story

    http://www.ihpartsamerica.com/forums/basic-tech-questions/9019-fuel-float-struggle.html


    I have rebult my carb after replacing the fuel tank, sender, cleaned the lines, verified that the Mechnical pump is pumping gas into a beer bottle. the engine runs off the gas in the bowl when started


    I took of the two bowls off and cleaned and replaced everything with a correct rebulid kit and I'm having problems. ( Holley 4150 450 cfm ) the car has been sitting for 12 years and I could get the engine running fine except this last year when it would not.


    My problem I have been trying to set the float on the primary but my real concern is the fact that when I get the engine runing it starts at ( By ear) 2500 to 3000 rpm. it will not idle. this Holley was NEW 12 years ago when I put it on and it ran great.

    So with very few obvious reasons I cant understand why the choke is running the engine so high. Everything is relaxed in the linkage and I never opened the the body of the carb on the rebuild. The metering block had clear openings that I cleaned and I replaced the power valve.

    I flushed some berrymans down the primary air tube okay. the secondary air tube shows me a leak on the flow dripping off the top of the bowl to the rear.

    Anyway its a long process I find...can anyone help?

    Thanks
    Lawrence

    100_7029.jpg 100_7030.jpg 100_7032.jpg
     
  2. zrayr

    zrayr Well-Known Member

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  3. rsimkins

    rsimkins Well-Known Member

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    Lawrence,

    You might also try posting over at Ed's Carburetor Forum (http://www.network54.com/Forum/88781/). While the subjects seem to center around Autolite carbs, they get their fair share of Holley questions as well.
     
  4. malstrom

    malstrom Member

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    Thanks Mr r simkins

    I did try ... and I am still waiting over there. Perhaps you can help. I am having trouble setting the fuel float. I keep thinking my high running idle has something to do with my float level. I know that's not right but. I still need to set the level,..

    So after fussing with the screws too much I just got mad. Took off the carb and removed the front bowl. The rear is set nicely and expelled gas from the pipe when I turned the carb over. But the front bowl was empty also empty : the the inline fuel filter.

    So here's 'my photos of trying to set the Float. I read online where I can invert the bowl and set the float by eye. Or measuring from the heel or toe. I don't know which. If you can see my photo what does this look like to you? Good or bad?


    Could a high rpm idle be caused by the rear bowl /jets?

    holley 4150 heat choke vaccum secondarys

    Warmly

    Lawrence
     
  5. BillH

    BillH Well-Known Member

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    If there is fuel in the primary bowl, It sounds like one, or both idle passages between the throttle body and the main body may be plugged. To check this:
    1) Remove the carb, tip it over and shake any gas out.
    2) With the carb on the bench, inverted, remove the clip connecting the secondary diaphragm to the secondary linkage. Don't lose the clip.
    3) Remove the base plate from the main body. (Rather large phillips head screws, usually 6 or 8)
    4) Look for small holes drilled on front of the primaries. There is a slot that the primary butterflies uncover when they start to open. Make sure that the passages and the slot are clear. Use a good quality spray carb cleaner with the plastic wand and blow out all the passages.
    If replacing the gasket is necessary, make sure the new gasket is a perfect match!! All the holes have to match the throttle body.

    If there isn't fuel inside the primary bowl but in the secondary bowl, you have a faulty primary needle and seat assembly. Carefully remove the needle and seat and either clean it or replace it.
    Good Luck
     
  6. malstrom

    malstrom Member

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    thanks Bill

    for the help and brainstorming . I took off the carb from the car and I'm sure that rear secondary carb idle screw is the same as it was before I did the rebuild. I never opened the carb body. Ii think the rear plates are well closed. I did not want to cut open the body just yet. But I did suspect a new problem bottom of thread.



    ://malstrom.startlogic.com/comp/100_7195.JPG






    This would be a vacuum secondary heat carb





    I also took off the primary bowl to try to set the float.



    http://malstrom.startlogic.com/comp/100_7148.JPG
     


    I read somewhere ... you could invert the bowl and set the carb level by eye. Which I did. I will re-assemble the carb and put it back on the engine.
    But I don't think this will solve my high idle problem if I get the float level correct.


    I also took off the primary bowl to try to set the float.



    http://malstrom.startlogic.com/comp/100_7148.JPG

    Is there some kind of Linkage inside the carb body that is stuck on a high idle position?


    One week later....

    I can get the car to run badly an when running I can force the full open choke plate closed which settles my down my high idle. ( Wont that run the mixture lean and accelerate the engine for cold starts.)???

    Now I have a new problem. I get the car to run for about 10 seconds at high idle and roughly. The engine runs down and stops. This has repeatedly been a little common in my efforts. I remove the site plug on the carb. Shake / Rock the car. No fuel spills from the bowl. I check the clear fuel line and again no fuel line in the clear filter.

    So can anyone tell me if I switched the fuel lines on the pump? The grey hose goes to the engine the gloss black goes to the new tank, new sender, and 4 gallons of fuel.

    I guess I could take off the lines..... have someone crank the engine and thumb the ports?

    Does any one know if there is a service that can rebuild a 200 dollar carter pump? Is it worth it?


    The strange thing is I think this is correct.. I can put a beer bottle on top of the engine to catch the gas as I crank the engine.

    http://malstrom.startlogic.com/comp/100_7200.JPG

    Much thanks

    Lawrence

    Thanks

    Going crazy
    Lawrence
     
  7. BillH

    BillH Well-Known Member

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    The secondary plates are designed to be "slightly" opened at anything but WOT and the secondary side has an idle circuit. This is to insure fuel flow through the secondaries to prevent fuel stagnation. The secondary idle circuit is not adjustable and it won't supply enough fuel to keep the car running if there is problems in the primary side.

    The problem still sounds like what was outlined in my original reply. Did you remove the throttle body from the main body?
     
  8. malstrom

    malstrom Member

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    Sorry Bill for not being clear. I did not crack open the body. I will pursue replacing the fuel pump first just to get that out of the equation. or rebuild it....... which will take time before I start again on the carb.


    Thanks!
    Lawrence
     
  9. malstrom

    malstrom Member

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    Hi Bill

    Yes sorry about the delays I only really get Sundays to work on the car and life does take its time. I have started putting in mid week attempts now. I am able to get the disconnected fuel line at the carb to pump gas. I collected about half of a 1 pint 6 ounce large beer bottle of gas on a three second engine run that seems to die itself from fuel shortage? . I reconnected the fuel line to the tank run again and I get about a quarter that amount 4 ounces. But I think the lines and tank are fine. Brand new tank and sender and four gallons of gas in a 16 gallon tank. I did find that a fuel cap was causing drag when connected.


    In my above runs I found that I was consuming gas from the primary bowl of course. I refill at the carb vent pipe to save the battery cranks.


    I now have the fuel system at the bottom of the engine in a 2 gallon can.


    A week passes.


    Well I have only one general question. I can't get the engine to catch. Ignite and run. Ive done nothing to anything. The battery cranks ...seems as if its going to catch and does not. I take off the site plug on the primary bowl and shake the car. No fuel spill. So I have used a funnel type syringe in both the site plug hole and air vent pipe on the primary bowl to insert gas. I pull gas from a 15 ounce clean glass jelly mason jar.


    So I input about half the bottle or 9 ounces of gas and still no fuel on rocking the car. Where is the gas going. There are no leaks, the manifold is dry. Could the carb pass gas inside the manifold to the Cylinder chambers and I have a flooded condition? I do not smell gas on cranking.



    I've lost my mind

    Warmly,
     
  10. BillH

    BillH Well-Known Member

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    A few ideas:
    I take it that the engine has spark, (if you pull a plug and, with the wire attached lay it on the intake and crank the engine you have spark.)

    Fuel in the bowl always goes to the lowest point in the bowl, which is the accelerator pump. Is there fuel coming out of the accelerator pump squirters that are located under the choke plate on the primary side of the carb?
    The only thing that can prevent fuel from entering the bowl is if the needle and seat is either stuck or the adjuster is screwed all the way down.
     
  11. malstrom

    malstrom Member

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    HI Bill

    I have no leaks anywhere but now that you mention in it the reason I did the rebuild on the carb is that I could not get primary jets to squirt like I remember from my autolite 20 years ago when I was a kid. I did the rebuild right. Opened only the bowls and cleaned.

    Needle??? I guess you mean the primary float needle yes changed that in photo number 7148 you can see how I adjusted the float

    the you tube show my condition after the rebuild with fuel line to the tank with a unknown to me then a vented but too restrictive gas cap.

    I could get it to run ,,,,,,

    http://youtu.be/VadbU_BUALI


    after the you tube run I get just the cranking problem no fire and black hole for the primary bowl.

    Thanks

    Lawrence
     
  12. BillH

    BillH Well-Known Member

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    In the past, I have seen problems with the Holley needle and seat adjusters located on the top of the float bowl. The adjuster consists of a hex nut, (5/8 inch wrench size if memory serves) that engages into the top of the needle assembly. Turning turning this adjuster raises or lowers the needle and seat assembly and thus adjusts the fuel level. Right hand (clockwise) to lower and left hand to raise the level. The lock screw has a straight screwdriver slot and is only used to lock the needle adjuster into position. There should be two gaskets, one on the bottom of the adjuster nut and one on the top. I adjust it using a box end wrench. loosen the nut and turn the adjuster nut counter clockwise about a 1/8 turn at a time until I just see fuel at the bottom of the sight plug. The fuel level controls the timing of the main circuit; Too low, you have a off idle flat spot. Too high and the engine runs rich, you sometimes see fuel dripping out of the venturi cluster when the engine is idling.

    What I have seen happen is when the unit is installed, the adjuster is turned down so far that the needle assembly slips out of the slot in the adjuster nut. Turning the adjuster nut now makes no difference since it's not engaged in the needle, you can turn on it until the cows come home and it will never raise the fuel level. I know guys who did this and it practically drove them nuts. I would unscrew the lock screw and lift the adjuster nut off of the carburetor. You should see the top of the brass needle assembly sticking out of the float bowl at least 1/8 inch and the slot on the adjuster nut should be engaged into the top of the needle assembly. In extreme cases the adjuster needs to be removed and the needle assembly carefully unscrewed using a pair of needle nose pliers to just catch the top of the needle and seat assembly.

    If the needle was screwed down too far, it would explain why the filter is empty because, with the needle and seat bottomed out there is no way for fuel to flow into the bowl.
    Check this out.
    Thanks
    Bill
     
  13. malstrom

    malstrom Member

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    Hi Bill


    Thanks for the thoughts on the needle valve. I can understand only to the point where you start talking about using needle nose pliers. There is no object inside the brass value to pull out. I guess your just trying to say you want to get a grip on the needle valve to unscrew it.

    My value is flush with the Adjusting nut. I 've tried to enclose a photo.

    Also side story. I'm refilling my leaky Transmission to check the leak points when I notice oil on the bottom of the tranny housing. Can anyone tell me why oil would be there? Its definitely black oil. I have no problems with the engine. The valve covers are good , as well as intake Manifold seals I think also. Oil does not mix into the tranny?

    Anyhow one problem at a time right. I think I'm good on the bowl level. But of course the engine 'runs way' as noted in the you tube video.

    100_7219.jpg 100_7223.jpg

    Warmly
    Lawrence

     
  14. malstrom

    malstrom Member

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    Hi Bill

    Just wanted to ask before I went that direction




    Would you know if there is some kind of pressure test tool that can be used on the outflow of a pump to see if the pump has failed ? I can fill a beer bottle with gas but I'm still wondering if there is a intermittent or faulty pump. My fuel filter is empty as in the below video but that I think is only temporary until the pump can refill repush it.

    Q. should the engine still run on a properly set needle valve if there is not fuel pressure.. I mean is the Carb bowl gravity fed into the engine and will it run for a few seconds?

    https://www.youtube.com/watch?v=VadbU_BUALI

    Thanks Bill or anyone that can help!

    Lawrence






     
  15. BillH

    BillH Well-Known Member

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    One more thing to check; Is there a possible air leak on the suction side of the fuel pump? The flex hose between the pump and the steel line and the flex hose between the tank and the steel line need to be checked along with the steel line (Maybe worn through somehwere?) that they have tight clamps and the hose is in good shape. A air leak here will not drip fuel but it also won't let the pump pull fuel out of the tank. I have seen new pumps condemned as defective when the problem was an air leak in this area. Fuel pressure is no problem checking, get a fuel line "T" and connect a fuel pressure gauge. Should have 4.5 to 7 lbs. pr. sq. in. pressure.
     
  16. malstrom

    malstrom Member

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    Hi Bill

    One thing I'm going to try beginning this week is to re-test the fuel pump under the previous condition I did before. I placed a two gallon gas can under the engine and pulled from there into a Beer bottle. Tested both sources ... an pull from the can and a pull from the rear fuel tank.

    Here's the change....I did those tests with out a fuel filter on the expel top hose. ... since the video shows an empty fuel filter .... I will rerun the test(s) with the fuel filter on the expel hose to see if I can put fuel into a bottle. Maybe the fuel is just not getting to the carb. I will release my results next time.



    http://www.youtube.com/watch?v=VadbU_BUALI


    I don't think a "T" line check from a gauge kit that I could buy from the parts store will help. As I can't get the engine running ... then get out of the car and my head down to the gauge to see the effects . It needs to be reliably running.

    I may have to

    http://www.cjponyparts.com/product....ign=shopping&gclid=CPmoxOz9xbQCFUdxQgodIXsAQw

    Thanks again!:thumbup:

    Lawrence


     
  17. OVERRIDE

    OVERRIDE Well-Known Member

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    Check your engine oil if you smell a lot of gas in the oil change it . If you get a lot of gas in the oil it will wash the oil of the cylinder walls and that can cause it not to start to. That is only if fuel was leaking in the carb and down the intake.
     

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