Sorry if this has been posted but I’m new to the page and need some help. I’ve got a 71 with a 240, original cater carb. It’s just been rebuilt and runs good. After driving it a while and it sits for about 30min it’s really hard to start. I’ve got to pump the pedal several times and then it runs. After it starts I can cut it off and it will start right up every time, but when it sits for a bit I have a hard time starting it again. Any help would be great.

Carter carb single barrel
work that has been done:
new carb rebuild kit
new fuel pump and filter

 

Welcome to the forums. Sounds like it is heat soaking and boiling the gas out of the carb. Typical on these old trucks.

The second issue could be from a float level just a bit too high. When it shuts off, it dribbles fuel and floods the engine.

Remove the air cleaner and when you shut if off(after a long drive), watch to see if you see a light fog coming from the carb. That would be fuel dribbling down into the hot engine. Try adjusting the float down just a touch.

The heat soak issue is a bit harder to fix. A heat isolation spacer under the carb would help keep it cooler. Maybe have just put an electric fuel pump on the truck to reprime the carb before a hot restart.

 

I’ll try the float issues first. Thank you for the advice.

 

Heat soak can be alleviated by a thermally insulative gasket. The original gaskets contained asbestos which partially insulated the 1bbl carbs from transient manifold temperature fluctuation, such as after engine shutoff. Silicone baking sheets are a passable substitute. Trace around the outline of the cardboard gasket from the rebuild kit on the baking sheet and cut it out. Also, as suggested above, carefully check the float to ensure it's not flooding.

https://www.walmart.com/ip/Silicone-...hite/479734120

 

Insulate the metal fuel line. I bought mine at O'Reilleys. I think it's a Mr Gasket product. It's fiberglass covered with foil:

It's long enough to go from the fuel pump to the carb. It should work fine on a 240 engine too.

 

I guess im lucky, never had that problem with the 240. mine has the ford 1101 carb on it factory.
im just using a rubber fuel line from the pump to the carburetor. would this matter as far as vapor lock is concerned?
maybe the steel line absorbs more heat than a rubber fuel line?

 

Why would you not see the mist if it was boiling (steam?) the fuel also?
I don't think saying the mist is a float to high as it could also be boiling the fuel.

This is an issue with a lot of carb motors in older cars & trucks with the gas made today.
Have you seen how fast gas evaporates just in an open container? Add heat and it does it even faster!
You don't see this on any EFI motor as the system is under pressure and a sealed system.

I don't have a carb motor on the street yet but the fix I have seen posted besides a insulated gasket or plate between the intake & carb is to add a little diesel fuel to the gas.
I think it was 1 gal diesel to a tank of gas. Again I don't have a carb motor on the road but if I run into this issue I will give this a try.
If you want do a search in the 80-86 truck area for "hot start" as it has been covered over there.

BTW the electric pump is NOT a good fix with out safety items in place like a oil PSI switch that will turn the pump off if no oil psi and the crash switch that also opens if in a crash to turn off the pump.
If you don't believe me look up in here or was it the dent side "truck fire" a few have lost trucks do to fuel pumps keep running with motor off till the battery stopped working from the fire.
Dave ----