Hey guys. It's been awhile since I've posted. Sorry. Got a quick question to see if anyone can help. I can't figure it out. I've got a 1950 Buick & after I drive it for about 15 min. It's starts to stall or act like it's gonna die while sitting at a stop light or a drive thru. I parked it in the driveway, opened the hood & watched the carb. Every time it would try to stall gas would shoot out of a hole in the side of the carb. I took the carb apart & blew it out & checked the needle & seat, which is the new flat style with a rubber pad on it that seats. I rebuilt the carb a few months back. Attached is a you tube video link of what is happening. Any help would be great. Thanks.
Wot the hell... maybe a stuck float? Looked like it started and then stopped. Odd for a hung up float.
As in boiling or percolating? Some carbs have an anti-percolation flapper in them, not sure on the old Buicks though. You could wrap the fuel line in cold rags to see if you can prevent it from happening. It seems to recover quickly. Need the Beaner or Jalopy Joker to chime in.
I'm gonna try insulating the fuel lines to see if that helps. In the mean time I'm hoping that the Jalopy Joker or Beaner do chime in. Thanks.
fuel percolating , have to get the fuel line out of the fan air flow and away from block , also thicker insulator or a aluminum heat sink between carb and manifold will help ( the aluminum is 1" wider than the carb base in the wind ) also check your heat riser valve to see if its loose if it has one , if it sticks it will cook the snot out of the manifold
That's about the strangest thing I've seen in a while. At first, I was leaning towards stuck float, but after seeing how it seems to "recover" after blowing it out, I'm with the rest and leaning towards boiling/percolating fuel. I've worked on a shit ton of carbs through the years (restoring vintage British stuff for 20+ years daily) usually when there's a stuck float, it just blows the fuel and keeps blowing it. Your Buick's issue is odd . I can't wait to see what solves it.
All good ideas for an odd problem. How close is the hard fuel line to the exhaust or intake? Try to insulate that too. Lots of products are available and will slip over the lines easily enough.
Doesn't seem to be the heat riser. I lubricated it & made sure it was moving freely. Ran the car & still did the same thing. Where would I get an aluminum heat desk to put between the carb & manifold. I already have a thicker fibrous one in place, which may or may not be working. I still need to try insulating the fuel lines & I wouldn't say the fuel lines are that close to the manifold. Maybe 8-10 inches away. I'm going to also try checking the thermostat to see if the motor isn't cooling properly. Could that cause percolation?
you can make the heat sink from some aluminum sheet .060 to 1/4 plate but the thing is you want it to hang out so the fan air will blow over it to pull the heat out of it ( kind of like this ) the sheild does 2 things reflects any heat from below , and pulls it out of the base of the carb ( heatsink ) it will get hot , put the plate against the manifold then the insulator pad between it and the carb . another thing I thought about is what happened on one of my boats the motor would surge , what was causing it was crap in the fuel tank plugging up the inlet and when the crap would wash off the inlet the pressure of the fuel would over power the carb float bowl from the pressure , check the filter after the pump if you have one or the pump itself as it might have some crap in the valves . on the exhaust riser check to make sure the shaft is turning as I have had some where the weight turns ( and eventually fell off ) , but the shaft was siezed solid and the valve was partially shut in the manifold ( you have to take the pipe off and do a visual.
Hey guys. So I think I'm 95% sure I've got it figured out. When I rebuilt the carb the old style needle valve was replaced with a new style needle valve called a Daytona valve. (See pics) Instead of a sharp tapered valve it has a flat bottom with rubber on it that seats. I pulled the Daytona needle valve & put the old style needle valve back in. Put everything back together & ran car for 30 min. I couldn't get the car to reproduce the fuel spitting issue with the old style needle valve. Knock on wood. I'm gonna have to give it another In N Out drive thru test on a hot day to really know for sure. That being said I think I must have had the float adjusted wrong with the new style Daytona needle valve. I never adjusted the float when I rebuilt the carb. I just assumed they both used the same float adjustment. Ughhhhhhh!!!! I'm a little confused on why this would fix the problem though. i would really like to put the daytona valve back in because it seems like a better design, but I'm unsure how to adjust the float properly to make it work. Thanks again for all of your suggestions & help guys. You all really help with getting the creative juices flowing.
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