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Technical Carb going dry!

Discussion in 'Traditional Hot Rods' started by RednekYoga, Feb 22, 2020.

  1. RednekYoga
    Joined: Feb 2, 2019
    Posts: 81

    RednekYoga

    Hey HAMB,

    My 289 2bbl keeps dying while I'm driving, and the carb is going bone dry. When I dump gas in the carb, she fires right up and drives like a quarter mile and then same thing. When I'm idling, it doesn't cut off, and I can rev it and rev it, and hold it at 2500rpm and it doesn't die. Soon as I'm driving, it quits pretty quick. I have a new fuel pump and carb on there. Any ideas?

    Thanks,
    Aaron
     
  2. Johnny Gee
    Joined: Dec 3, 2009
    Posts: 14,364

    Johnny Gee
    Member
    from Downey, Ca

    Fuel filter. Driving requires more fuel than free wheeling in neutral. I'd also check to see if new fuel pump is working correctly? Also is float in carb set correctly? New means nothing anymore.
     
  3. RednekYoga
    Joined: Feb 2, 2019
    Posts: 81

    RednekYoga

    Fuel filter is clean. I think the float is a suspect now that you mention it, but to be sure, it's not cutting off when I brake or turn. It's just like the carb runs dry under driving conditions. Still potentially a float thing? Thanks!
     
  4. How was it driving before the new fuel pump and carb ?

    Tommy
     
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  5. RmK57
    Joined: Dec 31, 2008
    Posts: 3,123

    RmK57
    Member

    Check the float level first and see if that checks out. If it's the original fuel line that could be a problem also. Take fuel line off the pump and get someone to crank the engine with line in a container to see how much volume you have coming out.
     
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  6. David Coleman
    Joined: Oct 15, 2019
    Posts: 29

    David Coleman
    Member

    Two ways to see fuel pressure. #1 is kind of dangerous, so be careful, and that is to plumb a tee fitting into your carburetor supply line and rig a mechanical fuel pressure gauge up where you can see it while driving down the road. If the fuel pressure drops to ought, trouble shoot the supply side until you find the blockage. Probably going to find a MacDonald's napkin floating around inside your gas tank. #2 is lot safer and could be permanent if you want. Source and install a low pressure, ELECTRIC oil pressure sender into that tee fitting, and mount the gauge in or under the dash. The reading might not be spot on accurate, but it will show "no pressure" if and when you run out of fuel pressure. If you DON'T run out of pressure when it stalls out, you have a carburetor problem (plugged p***ageways, float errors, sticky needle and seat, plugged internal fuel filter). If you DO run out of fuel pressure ( I have done the following - - just because I can) you might try rigging a little supply tank, like a surplus lawn mower tank, to run the car down the road - - - just for grins, and to prove to your self what's up. You don't even need a fuel pump, just racer tape a tank high up on the roof, and gravity feed the carb. It will run OK if the carb is OK. Again, this little test will reinforce the fact that your fuel line has a hole, or is plugged, filter is plugged, fuel tank is layered with **** or is building a strong vacuum, or something along the lines of a McDonald's napkin, foam filter of the fuel pick up tube, leaf or dead mouse.
     
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  7. 67drake
    Joined: Aug 8, 2008
    Posts: 816

    67drake
    Member
    from Muscoda WI

    My Mercury did the same thing. The fuel tank was full of rust, and the pick up screen was clogged. It would start and idle fine, but when driving the bowl would go dry.
     
  8. lippy
    Joined: Sep 27, 2006
    Posts: 6,856

    lippy
    Member
    from Ks

    Also check the rubber hose from the tank to the line. Look for cracks or splits. Could be ****ing air there. Lippy
     
  9. hotrodjack33
    Joined: Aug 19, 2019
    Posts: 4,892

    hotrodjack33
    ALLIANCE MEMBER

    Yup, had the same problem. Years ago I stuffed a 425 dual quad Buick engine into a 48 Ford Pickup. I could drive it about 3 miles and the carbs would be dry. Let it sit 5 minutes, pump the hell out of it and it would drive 3 more miles and die...would do that all day long. Figured the mechanical fuel pump couldn't keep up with the carbs, so I added an inline electric pump. That made it worse...could only drive 1 mile at a time before it would die. :(
    It ended up being the 8 inch long rubber hose from the gas tank to the fuel line. With the mechanical fuel pump, it would **** closed after about 3 miles. Adding the electric pump just made it **** closed faster.
     
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  10. JeffB2
    Joined: Dec 18, 2006
    Posts: 9,665

    JeffB2
    Member
    from Phoenix,AZ

    6-bangertim and Boneyard51 like this.
  11. clem
    Joined: Dec 20, 2006
    Posts: 4,683

    clem
    Member

    Read post 4 again, if there were variances between ‘before’ and ‘after’, the answer may be more obvious.
     
  12. carbking
    Joined: Dec 20, 2008
    Posts: 3,959

    carbking
    Member

    My guess also.

    Jon.
     
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  13. RednekYoga
    Joined: Feb 2, 2019
    Posts: 81

    RednekYoga

    Before the new carb and pump it was stalling when I stopped. Harder I stopped, harder it died. After new parts, the problem changed to my current situation, but after some carb adjustments it went away. I drove it around quite a bit and it ran normal. Now after sitting for a month (****py Washington weather), it's back to its old shenanigans.
     
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  14. jimvette59
    Joined: Apr 28, 2008
    Posts: 1,144

    jimvette59
    Member

    Rubber fuel lines have been known to collapse when ethanol softens the inner rubber.
     
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  15. RednekYoga
    Joined: Feb 2, 2019
    Posts: 81

    RednekYoga

    Pulled the tank and drained it. Pretty dirty and rusty especially toward the end. Sending unit is super rusted in. Might be time for a new tank.
     
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  16. Yep,,,check that sending unit well,,,I have seen the fuel tube plugged up with junk .
    A few years ago I went through this with my Challenger,,,it had sat for some time in the ba*****t.
    The fuel had evaporated from the tank,,,no big deal I thought .
    Worked on it for weeks,,,,,new fuel,,,,,barely a few drops came out .
    Holley blue pump,,,,it must need a rebuild ?,,,,,,worked,,,just no fuel came out,,,other than a very slight amount.
    Even dropped the tank,,,,sending unit looked fine,,,,,,filter on end of tube looked great,,,,clean and pretty.
    New fuel lines,,,,replaced everything I could think of .
    Finally dropped the tank again and inspected the sending unit without the filter on the tube this time .
    Found the problem,,,,,,the old gas had some additives in it,,,,when it evaporated,,,,the additives solidified inside the tube .
    Had about a two inch solid plug inside the tube,,,,,removed the funk,,,,,washed it really good.
    After that,,,,it flowed fuel just like the old days,,,,blue pump to two 750 ‘s,,,,ran like a stripe- edd *** .

    The sending unit might be your problem as well,,,,hope it works .

    Tommy
     
  17. 6-bangertim
    Joined: Oct 3, 2011
    Posts: 411

    6-bangertim
    Member
    from California

    Cut the fuel filter apart, look for traces of rust or rubber between the pleats of paper. Today's gas is HARD on old rubber lines, to the point of disolving the rubber. If the pick-up inside the tank has a nylon sock, it could be varnished up to the point of restricting flow. If you haven't replaceed the fuel filter, DO IT!
     
  18. 67drake
    Joined: Aug 8, 2008
    Posts: 816

    67drake
    Member
    from Muscoda WI

    Good that you found that.
    If the tank is in good shape otherwise, when it happened to my Mercury,I used that tank sealer found at auto parts stores. It’s run great ever since.
    It a bit of a process, but cheaper than a new tank. I’ve used it a few different times,and also on a couple of old metal tank motorcycles.
    Good luck.
    I’d put a new fuel filter in too, since your new one probably is already trashed!
     
  19. RednekYoga
    Joined: Feb 2, 2019
    Posts: 81

    RednekYoga

    Hey y'all, thanks for all the help on this. New sending unit and tank cleaning did the job!
     
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  20. Johnny Gee
    Joined: Dec 3, 2009
    Posts: 14,364

    Johnny Gee
    Member
    from Downey, Ca

    ^^^^^ Thanks for the update.
     

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