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Fuel delivery issues in 283

Discussion in 'The Hokey Ass Message Board' started by sammyg, Dec 19, 2010.

  1. sammyg
    Joined: Dec 30, 2007
    Posts: 183

    sammyg
    Member

    I've searched high and low, and tried lots of things, but I can't find anything.... I'm not sure if I'm vapor locking or not, but... 1965 Chev 283 in a 47 Willys CJ2A (I know it's not true hamb material) but you guys may be able to help me... I'm running a stock mechanical pump with the extra capacity, no fuel lines are near the exhaust, it's 3/8 from the tank to the carb. QJet with Aluminum Q Jet intake. 7PSI of fuel. I'm running at idle 210* and in motion 200*. When I hit half throttle or so, I run completly out of fuel. It surges, sputters, dies. Pull over, crank it over until fuel gets back into the carb, it will start and run fine at idle, crack the throttle and it bogs down, hesitates and dies. Not only that, when I watch the injector pump work and squirt fuel into the primary's, I can see the fuel vaporize and smoke out the top.
    I heard that there were several different fuel pumps and length of stroke on the pump, can this be the issue for me? I don't know how a mild 283 can drain a QJet.... But, any ideas would be perfect.
    Thanks
     
  2. dbradley
    Joined: Jan 6, 2007
    Posts: 1,036

    dbradley
    Member

    Could have the float level set too low. The bowl capacity is not very big when all is correct. Also check the 'rock' filter in the Q-jet inlet for blockage.
     
  3. sammyg
    Joined: Dec 30, 2007
    Posts: 183

    sammyg
    Member

    The carb was just rebuilt locally by a reputable carb shop...The guy who did it is about 60 or so and knows his stuff. I know it's running a little rich right now. How can I check the float level?
     
  4. 26 roadster
    Joined: Apr 21, 2008
    Posts: 2,019

    26 roadster
    Member

    I had a problem like this on my 41 chevy, 425 olds 2bbl, I added a electric pump and still it would run out of gas. pull over run the pump for a few minutes then go for a little longer, then run out again. drove me crazy, pulled the original tank and when i disconnected the fuel line i found a piece of twine in it. removed twine, cleaned tank and replaced, no problem. check your fuel line and tank if it hasn't been done
     

  5. sammyg
    Joined: Dec 30, 2007
    Posts: 183

    sammyg
    Member

    New fuel tank, new pickup, new lines, new filter element....Everything in the fuel system was gone through when I did the motor swap. I did run it out of gas in the tank once, but that was 1 gallon it in it to set timing and eveyrthing....Now I keep it full. 3/8 from the pickup to the carb, and 1/4" return line.
     
  6. brad chevy
    Joined: Nov 22, 2009
    Posts: 2,627

    brad chevy
    Member

    Float either needs setright,could be needle and seat sticking ,just because everything is new doesn"t mean it automatically works right.Get you a manual out to see how to set the float ,the Quadrajet isn"t that hard to take the top off of.Before tearing into carb I would make sure you have a steady supply of fuel going to it.
     
  7. sdluck
    Joined: Sep 19, 2006
    Posts: 3,185

    sdluck
    Member

    Is the tank or the gas cap vented? Try test driving it with the gas cap off.
     
  8. is the tank or cap vented?
     
  9. ULRICK
    Joined: Sep 19, 2010
    Posts: 75

    ULRICK
    Member
    from Texas

    If you got a electric fuelpump around, get a jerry can of gas hook the can up to the electric pump and the carburator, this way you can narrow down your problem.
     
  10. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,523

    Roothawg
    Member

    Like everyone else stated, check your vent.
     
  11. 57283
    Joined: Oct 27, 2010
    Posts: 127

    57283
    Member

    I recently added a new carb, intake to my 283 and new gas tank. Ran great for 2 weeks and then this happened to me. It would idle good but when I pressed the pedal, it would die. I had a see through fuel filter and when I gave it gas, the gas stopped intering the filter and the motor would die. Not thinking it had anything to do with the carb, I changed the fuel pump and a few other things. Baffled me. I had a new carb but I took it apart anyhow. Finally fixed! A small amount of debris was in the main carb screen and it would idle fine but pressing the throttle got that debris moving and it would clogg the screen, kill the engine and the fuel would leave the filter. Sometimes something so simple can be so important! Been running great ever since. Good luck
     
  12. espo35
    Joined: Jul 16, 2010
    Posts: 310

    espo35
    BANNED
    from california

    Any 2-line fuel pump (Lester # 40987) for a small block is the same output, with the exception of a 1955-56 265 which has slightly less output. Look elsewhere for the problem.
    You say you have 7 psi of fuel pressure, so you obviously have a pressure guage. "T" it into the line from pump to carb and take a spin.

    Driving it with no fuel cap is another good suggestion.

    Lastly, and most obscurely, just because you have pressure doesn't mean you have volume. We used to put a sheet of Saran Wrap in idiot customers' cars. It would float like a jellyfish until it got sucked up by the fuel intake. Once the car would die, the plastic would float to the bottom of the tank and the car would run fine.

    Not too likely, but possible.
     
  13. sammyg
    Joined: Dec 30, 2007
    Posts: 183

    sammyg
    Member

    Drove it with no gas cap, again worked perfect at idle and low speed, and for a short period at WOT (better than the other day) but again would hesitate, sputter and die even at 6000 rpm. Crank it over until I get pressure again, and it would go. I was wondering if my gas was sloshing around in the tank, nope....Fuel is all aroudn the pickup, stand on it, about 5 seconds later it would hesitate and die.
    Fuel lines don't feel warm to the touch at all either.
     
  14. sdluck
    Joined: Sep 19, 2006
    Posts: 3,185

    sdluck
    Member

    Pinch off the return line and drive it.
     
  15. landseaandair
    Joined: Feb 23, 2009
    Posts: 4,485

    landseaandair
    Member
    from phoenix

    As mentioned earlier, check the internal filter. The rebuilder may have forgot to change it or the original looked clean and he left it in. I had one do the same thing to me and even though the filter looked clean, it had old varnished fuel on it that restricted flow.
     
  16. sammyg
    Joined: Dec 30, 2007
    Posts: 183

    sammyg
    Member

    He showed me the new filter he was putting in, it didn't have one originally when I got the carb. Good idea on pinching the return line.
     
  17. sammyg
    Joined: Dec 30, 2007
    Posts: 183

    sammyg
    Member

    It is a deep sump style pump, wondering if I should get a different style?
    [​IMG]
     
  18. Andamo
    Joined: Jan 10, 2006
    Posts: 523

    Andamo
    Member

    I wonder if the return line is sending fuel back to the tank and it's causing air to the pick-up ? Why are you using a return line in the first place ?
     
  19. El KaMiNo KiD
    Joined: Jun 15, 2009
    Posts: 509

    El KaMiNo KiD
    Member

    yeah..no need for a return line..
     
  20. noboD
    Joined: Jan 29, 2004
    Posts: 8,458

    noboD
    Member

    Isn't 7 psi kind of high?
     
  21. 61 chevy
    Joined: Apr 11, 2007
    Posts: 891

    61 chevy
    Member

    call the carb shop, see what they say,
     
  22. sawbuck
    Joined: Oct 14, 2006
    Posts: 1,909

    sawbuck
    Member
    from 06492 ct

    check the sock on the pick up tube in the fuel tank....
     
  23. You probably have new hose on yours, but I have had problems before with the fuel hose from the tank to the metal line. A break from dry rot is not always readily visible, but if you are sucking air you won't run worth a darn. Seems to happen more with the current fuel.
     
  24. Hotrodhell35
    Joined: Oct 30, 2010
    Posts: 440

    Hotrodhell35
    Member

    Had the exact problem in my 348 chevy. Turns out the pushrod that actuates the pump was so worn down at higher rpm the pump would hesitate. Electric pump and a block off fixed that.
     
  25. check the fuel pressure when your having the problem, i think the fuel pump is bad. if so get one from a 1968 and older, then ditch the return line.
     
  26. sammyg
    Joined: Dec 30, 2007
    Posts: 183

    sammyg
    Member

    After crawling around under it, I noticed something odd, the fuel pump thought it was the bump stop and nailed the front diff...HARD.
    Crushed it. Swapped in a standard size pump with a return line, ran a bit better, no dice.
    Put vice grips on the return line, runs like a raped ape. So I reckon i'm onto my 3rd fuel pump now, or cap off the return. There's no sock on the pickup either... Just an AC Delco canister style filter in line. How would the fuel pump have been pushing all the gas back to the tank instead of to the carb, in 2 pumps now??
     
  27. 40fordtudor
    Joined: Jan 3, 2010
    Posts: 2,503

    40fordtudor
    Member

    Think I'd isolate the return line or install FI---the two likely don't mix. Path of least resistance or some such nonsense.
     
  28. it sounds like it is just dropping pressure not volume. get a non return line one from '70 and older.
     

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