vapor lock

[spikey]

in warm weather i,ve experience vapor lock. going up grades temp looks to be around 200. its happened five or six times. wrapped line with motocyce wrap.but it still happens?

[jon]

You may want to check if your gas tank vent is not plugged. I dont remember seeing a vent on my gas tank but from what I read on here there are different styles of tanks so you may have one that is vented.

[pop427]

I believe that the gas tank is vented to the charcoal canister as part of the ECS. ( Evaporation control system ). Need to know the year, Fed. or Cal. and GVW to know for sure.

[John Eversoll]

Ok, I'll put in my 2 cents...

Vapor lock....  is when the carb gets too hot....right?

I had the problem with my 71 BB Chevelle SS

Problem was solved when I put a "heat" shield under the carb"

You can get them at any Good Auto parts store".

You can try that... Remember the carb gets pretty hot under that dog house..
I removed the air compressor as it did not do anything for the cab

That will let more cool air in the engine compartment and take around 55 pounds of weight off the motor.

[LARRY RAY]

I also had bad vapor lock due to pulling a 24ft pontoon boat making engine temp go up. 1st attempt to correct was to make a coil of copper tubing about 10ft long and attach to upper side of frame in front of passenger side front tire. Rerouted fuel line to this and then to carb. Helped some, but still not 100% on a hot day pulling the grades. Second idea cured it. I mounted a rotary type AC-Delco electric fuel pump in line before the mechanical on the frame after the filter. It is also designed to let fuel pass through it without it being on. I wired it with a switch I mounted under the dash. Now when I have the problem, I flip the pump on and the problem is gone. What happens is the gas in the line to the carb get so hot it boils and the back pressure will not let the mechanical push the fuel through. So now I have that extra push and it works great.

[John Eversoll]

If " the gas temp is the problem, then re rout the fuel line

away from that nasty old exhaust manifold!!!!  and wrap it with with some type of heat shielding material....