Hey, new to sight. Need help with a 69 bird. Fuel keeps heating and as a result I get air in the filter and car will eventually die. I can see the air build up cause it's a clear filter before the carb. Moved lines and now it takes about 45 minutes for the filter to go 1/2 empty. I'm positive it must be heat because I ran out of a gas can not the tank to assure there wasn't line blockage, new mechanical pump to make sure it wasn't diaphragm related. The engine itself is not overheating, it stays steady at about 195. It is all rubber from pump to carb, aluminum from tank to pump. Will going aluminum from pump as much as possible help to dissipate heat?? What about an electric fuel pump? But where do I wire in to?? Or a fuel line cooler? HELP!

I don't think it is heat. The air has to come from somewhere. The problem is somewhere between the pump and tank. The pump is sucking air. It could be problem with the pump itself. You have to find where the air is getting into the system.
Jim

replaced pump and same thing. Also I connected a new line directly from a gas can to the pump and same problem when it ran. I'm thinking the heat is "boiling" the air out of the fuel and that's where it's coming from.

Look for a split seam or split flange on the fuel line from the tank to the pump, and from the pump to the carb. Also check for air leaking around the inlet fitting on your clear filter. Also pressure test your filter by capping off the outlet and applying 6 psi to the inlet and see if it leaks through the body or seams (use a bicycle pump with a pool toy nozzle). For you to have air in the filter, you either have a leak on the suction side of the pump (most likely) or on the pressure side, but you should be able to see or smell a leak on the pressure side. You should not smell fuel at any time. I don't like rubber fuel line over the engine; I use steel from the pump to the carb. Rubber eventually dries out and cracks, is susceptible to burning, and clamps can leak.

If you can't find a leak anywhere, try changing brands of gas. Look for non-oxygenated fuel. Ask the station owners who supplies the fuel and look on the fuel supplier's website. This should not be a heat related problem unless your fuel line lies directly on your intake manifold or block, in which case it is a routing problem.

Another idea: Add an electric pump in the back near the tank. That will eliminate any potential for vapor lock. Since you will be pushing the fuel, any air or gas vapor gets pushed out the carb.

By the way, the fuel drains back from my carb after I shut it down, sucking air back through the line and into the clear filter. I've got an electric pump with no mechanical pump and the electric pump allows some fuel to run back through the line. If your fuel pump is shot, it may be allowing the fuel to drain back and suck in some air.

I think gas boils above 270 degrees. If your line is that hot you better stand back because she's a gonna blow!!
Seriously, are you experiencing any problems related to the air in the filter? You just said it eventually dies after 45 minutes? Can you be more specific?
Jim

In about 45 minutes the filter will be 1/2 full and then it will kind of pulse with how full it is . If it runs long enough it will just get emptier until it runs dry and the car dies. New fuel pump and lines from tank to pump.

That sounds exactly like a bad fuel pump. The only other things are an obstruction or a air leak but you have ruled them out.
Jim

since you have a new pump, i would still check the pressure, like Fbody says, new doesn't always mean good... and also change to metal line. Vikki's bicycle pump trick sounds neat. your problem has me fairly stumped. if you are using winter fuel, or fuel from a particular station, i would change it. cold weather fuel is engineered to be more volatile at lower temps. oldtimers used to put wooden clothespins on their metal line to help cool it.

if you change to electric pump, you need to either find a wire which delivers 12v in 'start' and 'run', or wire directly to battery, incorporating a fuse and an on/off switch, which can double as a kill switch/anti-theft device. an electric pump will also require a pressure regulator to keep the pressure from getting too high.

I haven't experienced a bad sending unit yet, but what about a hole or split in the pickup tube? That could also draw air, which could collect in the highest point of the system, which would be the enlarged area of the filter.

Another temporary solution...remove the inline filter and the problem should go away, as the air won't collect and will be pumped right into the fuel bowl, where it will vent.

I will try metal lines since it runs the same whether I go from a gas can to the pump or the car's gas tank to the pump. I have a couple other questions. Can anyone e-mail me pictures of there lines from pump to carb. to see how it's routed. What temp. do you think is "normal" or "safe" to run at? I've seen these switches or units if I go electric pump that shuts off pump if oil pressure stops, has anyone installed one and know where they go or how they wire? I already have a battery disconnect/shut-off wired in to the console, should I have a separate one for the pump if I go electric? I know I'm full of questions, but I'm frustrated and stumped....