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No gas getting to carb.

Discussion in '1965-1970 Shelby Mustang GT350 & GT500' started by GCRIV, Jul 15, 2008.

  1. GCRIV

    GCRIV Well-Known Member

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    When I go to start my 65 289, I can see fuel in the fuel filter, but I have to prime the carb in order to get it to start. After I prime it, it runs fine, but if I let it sit for 20-30 mins., I have to prime it again. Any ideas?
     
  2. JamesFee

    JamesFee Well-Known Member

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    It sounds like the accelerator pump is not working correctly. A quick way to check is to look straight down the carb throat with a light (engine off) and pull the throttle linkage to WOT - you should see the gas streams in both primary barrels.

    You said that it ran OK - the accelerator pump diaphragm may be split and hemmoraging internally which would prevent it from giving the engine the correct volume of gas.

    Hope this helps
     
  3. GCRIV

    GCRIV Well-Known Member

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    I'll check, thanks for the info. I failed to mention, sometimes after it starts, it idles very high. I pump the pedal to see if the idle will come down, and it doesn't, it just idles very high.

    I live in a small town, should I take the carb. to somebody for replacement parts, or am I in for a new carb. :-(
     
  4. tesgt350

    tesgt350 Well-Known Member

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    When he says to use a LIGHT, I am pretty sure he means to use a Flash Light of some sort and NOT a bic Lighter.................:lmao:

    You might also check your Float Level, it could be leaking down.

    David.
     
  5. JamesFee

    JamesFee Well-Known Member

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    This is where it goes to your level of comfortability. I would say that the accelerator pump would be a nice project to start with if you were so inclined. It is a squarish housing with a lever on the side of the carb held in with 4 screws.

    I would say that if the accelerator pump has deteriorated - the other gaskets & such are probably in the same state. Very few parts can make a car run as good OR as bad as the carb.

    If you are in it for the hobby, I'd recommend trying it yourself - get a rebuild kit and just be careful to put back all the parts :laf: It truly isn't too difficult.

    That being said, if you just want to make it run - you could find a rebuilder, either local talent or someplace like PonyCarbs who specialize in these carbs.

    It would be a rare set of circumstances to necessitate a new carb - they are pretty stable and very rebuildable.


    :eek: oops, yes, definitely NOT a bic

    Good Luck!
     
    Last edited by a moderator: Dec 1, 2009
  6. Mike Christie

    Mike Christie Well-Known Member

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    Also, check for loose or worn butterfly shaft on the primary side. I don't know if it would affect starting but it would affect the idle by allowing too much air to pass around the shaft. Look for worn venturi in the area of where the butterfly's are in the closed position, like at idle.
    Mike
     
  7. Doug_GT350

    Doug_GT350 Well-Known Member

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    If you do decide to rebuild it yourself (I've done a few) watch out for all the little ball checks when you turn the housing over! :eek:
    But when you bolt it back on and she fires up and runs nice, you get that good feeling. :thumbsup:
    The nice thing is a rebuild kit doesn't cost much, and the worse you can do is leave something off or in backwards. It's a "nothing lost - experience gained thing". If it doesn't work then you take it to someone!
     
  8. GCRIV

    GCRIV Well-Known Member

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    No gas to carb. Checked fuel pump

    I am having trouble getting my car to stay running. When I looked at my fuel filter this morning, I noticed it was sucking the gas out faster than it would suck in. I thought maybe I had a vacuum leak, or something plugging up the line. So I changed the 3 rubber connections I had in my fuel line. Also when I had the fuel line off, I blew some compressed air back through the line to clear any possible blockage. After that, the car would start and run, but the fuel coming into the filter could not keep up with the fuel going out. So, I did the only other thing I could think of...I changed the fuel pump. After I did, it ran for a couple of minutes, and it was getting more fuel, but still not enough in my opinion. After it ran for a couple of minutes, it just quit. After a little investigating, it appears that the pump isn't getting it all the way to the carb. When I disconnect the line to the carb, there is absolutely no gas in it. Please help, I'm sooo close to getting this thing running, but yet so far. Please help.
     
  9. Bob Gaines

    Bob Gaines Well-Known Member

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    Re: No gas to carb. Checked fuel pump

    The description and the process of elimination you followed would make me suspicious of the gas tank . I have solved many similar problems with a gas tank change out. If you changed the fuel pump make sure your getting gas to the pump. When disconnected from the fuel pump even a half full gas tank should easily flow out of the hose end that connects the gas tank to the fuel pump. I have seen gas tanks that have enough rust particles, sediment etc. that even after blowing out the line the sediment particles quickly cover the fuel sender sock again and limit the flow once the fuel pump starts the sucking process. Mustang gas tanks are cheep enough it is not worth the time ,money and hassle resealing a nasty one . I hope this helps with your problem. Bob
     
  10. Texas Swede

    Texas Swede Well-Known Member

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    Re: No gas to carb. Checked fuel pump

    Had the same problem on my C-code Mustang and it turned out to
    be a clogged sending unit filter in the tank.
    Texas Swede
     
  11. GCRIV

    GCRIV Well-Known Member

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    Re: No gas to carb. Checked fuel pump

    Well, I replaced the tank last year. I would think the tank was clean enough, but you never know. I guess I could try that. But do you have any idea why the pump isn't pumping gas up to the carb. It is a brand new fuel pump, and I just can't imagine. When it was running with the old pump, it would suck the filter dry, but just enough was getting in to keep it running. Now, with the new pump, it doesn't appear gas is getting up the line to the carb. When I took the line off feading the carb, it was dry. And when I pump the throttle linkage, no gas is squirting into the carb. I am truly out of ideas. I'll check the filter in the tank, any other ideas?
     
  12. Shelby~gt350#3000

    Shelby~gt350#3000 Well-Known Member

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    Re: No gas to carb. Checked fuel pump

    Was the engine recently rebulit too? If so, did you tighten the nut on the fuel pump ecentric on the front of the engines camshaft? Did you remember to install the ecentric?


    Quick check regarding the fuel tank and lines, Get a clear glass bottle. Fill it with gas. Disconnect the fuel line at the fuel pump. Attach a hose from the pump to the bottle of gas. Disconnect the fuel line at the carb. Run the disconnected line from the carb to another empty clear bottle. Start the car and observe the fuel being pumped into the claer bottle. If there is little or no flow you know its either the pump or the ecentric on the cam. If you have plenty of volume (fuel flow) then the problem is from the fuel pump back. This diagnosis process will save you from pulling the gas tank.
    Jim
     
  13. GCRIV

    GCRIV Well-Known Member

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    Re: No gas to carb. Checked fuel pump

    Thanks for the tip, I'll try that in the morning. I just can't understand why when I take the line loose from the tank, the gas just pours out of there. Doesn't seem to be anything impeding the flow.

    As for the cam, I didn't have it torn down that far. Just had the timing cover and the fuel pump off, but didn't mess with the cam. This whole dad gum thing worked a couple of days ago, but now, nothing.
     
  14. tommyleea

    tommyleea Well-Known Member

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    Re: No gas to carb. Checked fuel pump

    Maybe your new fuel pump is bad, or your lever isn't positioned correctly for the cam to operate it. You could check fuel pressure with a guage. Or do like GT350 said and use the bottles. Cheers

    TommyJ
     
  15. GCRIV

    GCRIV Well-Known Member

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    Re: No gas to carb. Checked fuel pump

    I'm sure the position of the fuel pump arm is good. I had to press the pump down, so I'm sure the lever was under the cam. I thought about a bad pump. I wouldn't mind taking it back, I spent money on a new one only to find out the new one pumped less fuel than my old one!
     
  16. OVERRIDE

    OVERRIDE Well-Known Member

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    Re: No gas to carb. Checked fuel pump

    Did you look in a shop manual and do fuel pump test?
     
  17. GCRIV

    GCRIV Well-Known Member

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    Re: No gas to carb. Checked fuel pump

    Well, I took the line off the carb, and turned the car over. No gas was travelling up the line. After that, I thought maybe the line was plugged, so I just took the line off the fuel pump. Still nothing. I backed the pump out, and made sure the lever was under the cam. Tried again, still nothing. I thought maybe I bought a bad pump, so I put my old one back on. Repeated all the steps, still nothing. Please don't tell me there is something wrong with the eccentric on the cam! I just had the whole stinkin' thing apart, and didn't think to check that. I didn't think to check it because everything was working fine. How could this happen? One minute it's working, then it's not. I'm out of ideas. Please save this sinking stang!
     
  18. 65gtfastback

    65gtfastback Well-Known Member

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    Re: No gas to carb. Checked fuel pump

    I once had a similar problem that keep me guessing for days. My car would run with gas until it would get down to 2" or 3" inches of gas left in the tank.. At first I did not notice this correlation. But soon noticed it acted like it ran out of gas with gas in the tank. I was really puzzled. It turned out to be a pin hole in the line of the pick up/fuel sending unit, at the line's base next to the installtion plate. Car would get gas until it went below this area and then it was sucking air through the pin hole instead of sucking gas through the pickup screen which is somewhat lower. Remove your pickup/sending unit and make sure it has no leaks from pickup screen to rubber hose mount on other side.

    Side note is to try to always reuse an original sending unit if you can. They are much more reliable than a repro, even with 40 year head start...

    Good luck? Keep safety in mind while working on this.
     
  19. Shelby~gt350#3000

    Shelby~gt350#3000 Well-Known Member

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    Re: No gas to carb. Checked fuel pump

    well you NOT taking the advice I gave you about hooking up a rubber hose to a bottle. You need to elimainate the possiblity of it being the fuel lines, tank,pick up or sender. You need to see if the pump is working. If there is no fuel being drawn from the bottle it will be one of two things. Bad Pump, Bad ecentric. That's it that's all. This isn't modern day fuel delivery with relays, modules, regulators and computers-It's a pump, a tank and lines End of story. Your making this harder then it is.Your going from A-C, rather then A-B-C.

    Also, Remove the pump, look in the hole of the block, do you see anything there? Try the method I described. Ive been a mechanic for 20 years. Its not my first Rodeo. Diagnosing is done when you do it in the proper order.

    I have purchased brand new items before that were DOA right out of the box.

    SAFETY NOTE: REMOVE COIL WIRE FROM COIL BEFORE STARTING MOTOR

    Jim
     
  20. GCRIV

    GCRIV Well-Known Member

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    Re: No gas to carb. Checked fuel pump

    Maybe I misunderstood you. I took a glass jug, connected a new piece of fuel line, and submersed it. I then took the other end of the line feeding my carb, and took it off, and pointed it into a coffee can. When I cranked the car, no gas came out. Forgive me, but I thought I did what you told me to. I'm just trying to get my car running.
     
    Last edited by a moderator: Dec 1, 2009

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