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more weber carb issues

Discussion in '40- & 55-Series Tech' started by ken_79-fj40, Jul 22, 2005.

  1. ken_79-fj40

    ken_79-fj40

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    First of all, If I planned on keeping my 2f permanently I would throw this thing in the trash. But for now I need to make it work. My truck was running fine, then it got hot here. It would start up no problem when cold 1st thing in the morning. But whenever I would go out mid day for lunch, it would act like it was flooded. Basically the last 2 weeks I have had to hold my foot to the floor and crank the thing until it fired every day at lunch and leaving every night. But when it was warm, just hit the key and it fires instantly. So I figured the choke was malfunctioning. Last night I loosened the 3 screws on the choke housing and rotated it until it was wide open. Figured it might be a little harder to start when cold, but would be better the rest of the time. This morning, pumped it a few times, fired right up, I feathered the throttle a little bit, then it evened out. But it was idling at 1500 rpm! So I back off the throttle linkage a bit, it drops back to 700, and I head to work. After about 30 minutes on the highway It's idling at 1000 rpm. So I know the throttle linkage isn't returning all the way. But why the hell would the choke have any effect on warm idle speed anyway? I can't wait until I swap in the TBI 350. Fuel injection and no more points!
     
  2. ken_79-fj40

    ken_79-fj40

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    Okay, the throttle linkage is cured. But the thing still doesn't want to start when it's semi-cooled down. 2 hours after gettting to work, tried to start it, and nothing, held foot to the floor, kept cranking, and it eventually fired. Once running the thing is fine. Go into a store, come out, it fires instantly. What the hell? One of my coworkers just suggested possibly it's vapor lock?
     
    Last edited: Jul 22, 2005
  3. Pin_Head

    Pin_Head

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    It sounds like it might be siphoning gas out of the bowl when you shut it off. It you start it back up right away, no problem, because there is not enough time for it to flood. If you wait over night, no problem because it is cold and the gas has had time to evaporate. Shine a flashlight down past the throttle plates to see if raw gas is pooling in the manifold after you shut it down.

    If so, try vacuum cleaning the carb: Spray the inside with carb cleaner spray; start engine and rev to 3000 RPM; hand choke (put your hand over the top of hte carb) until it almost stalls; repeat 4-5 times. This pulls fuel out of all the holes and passages and sometimes cleans out plugged air vents (that prevent siphoning) w/o rebuilding.
     
  4. ken_79-fj40

    ken_79-fj40

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    Thanks pinhead, that makes sense. I also had an incident while out at lunch that could be related. I was turning left, across traffic. From a dead stop, give it gas and let the clutch out like normal. Just about stalls with oncoming traffic approaching at 50 mph. I pushed the clutch in, floored it , revving it to about 3800 and dumped the clutch. Layed about 10 feet of rubber, and scared the crap out of some lady, but didn't get t-boned. Drove fine the rest of the way back to work, drove fine for about 10 miles before. I'm picking up some gumout on the way home.
     
  5. ken_79-fj40

    ken_79-fj40

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    I got interrupted by having my appendix removed and minor hernia surgery. But heres the update. I tried pinheads hand choking with carb cleaner trick and the truck was running great. For about 25 miles. Then it started into it's stumbling at low rpms again and hard starting after it's been sitting for a few hours. So I had a friend pull the top of the carb off (because I can't do much for the next 3 weeks) and the bowl was clean. Pulled the small filter out on the carb inlet, and it was pretty gummed up. Cleaned that up, hoping it would do the trick, but no dice. So I'm going to try the hand choking thing again a few times, and a rebuild kit for the weber is on the way. Have to put a few hundred miles on it this weekend, hope she does OK.
     
  6. Pin_Head

    Pin_Head

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    Maybe the needle valve is dirty and doesn't seal so that when it is idling the bowl fills up and overflows. Can you see fuel coming out of the bowl vents when it is idling? (Bowl vents are typically 3/16 brass tubes cut on an angle that extend into the air horn.) Try cleaning it before you put the top cover on.
     
  7. andrewfarmer

    andrewfarmer

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    Given the choke's disconnected, when it's cold, does the pump still work?
    If it does, it may need a few pumps to get it going. Holding foot flat when cranking will lean out the mixture - you want it rich - pump that gas!

    While it's cold it will be short on power, esp at lower revs, because you've got the choke disconnected.
     
  8. ken_79-fj40

    ken_79-fj40

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    I didn't check the needle valve, but the bowl definately wasn't overfull. I seem to typically get the stumbling when I come to a stop and go to take off again. If I rev it up to 1500 or so before taking off it doesn't do it. I might throw a cap and rotor at it too, I cleaned the contacts on mine with some 2000 grit right before I started having trouble with this. Funny thing is , the hand choke deal with carb cleaner solved it temporarily. The real bummer about all this is that I currently can't do the work. I'm not supposed to lift more than 15 pounds for the next 3 weeks. So I shouldn't even lift the hood! Good thing this isn't my daily driver!