Fuel vaporization fix
I intentionally didn't use "vapor lock" because online every one had opinions on whether that term referred to fuel vaporizing in the carb or in the lines. Pedantic and I didn't want to start a whole thing, just needed the question answered about the vent line mainly. The fuel pump is mounted outside the frame rail on the passenger side, I initially wanted to fab something closer to the tank, but it is pretty isolated from any heat at the moment. I actually wanted to mount it so I didn't have to cut out a section of hard line at all, just rubber out the sender, into the pump, and rubber the the hard line. But the clearance to the rear end with the stock tank just didn't allow me to safely put it right at the tank with the pump that I bought. The factory hard line routing, coupled with the long tubes, coupled with gas quality, is what I'm sure caused this issue. The hard lines are sooo close to the headers right at the firewall. My IR was reading 145 on the lines, and 155ish at the mechanical fuel pump with the car off and the hood up after a short drive. I did think about finding nonethanol fuel to solve this, but this thing is a daily driver for me, and I just want to drive it and fuel it whenever and wherever it needs gas. I think I could have maintained the mechanical pump if I rerouted those hard lines AND installed the return line, I don't think the problem would have been completely solved without a return line, at least while using ethanol gas. Which in retrospect I should have just done that, because I don't trust nor want an electric pump. But that's what I did and I have no more issues now. For now, I still have the inlet and outlet looped with some hose on the mechanical pump and kept it on the motor, just as a back up for a roadside fix if and when the electric pump craps out. I also rerouted the fuel lines at the motor, they were not my handiwork, that's how I bought it. I flipped the hardline to the carb 180 degrees and routed the rubber line in a more factory way. I'm sure someone will tell me how my car is going to BURN DOWN IMMEDIATELY, but it's fine and everything is working well. The only thing burning is the inside tire on a turnI read most of the comments hear, but never heard of the old word, "Vaper Lock". Heat along the fuel lines is one cause. That is what you are getting. Heat from the headers, along the side of your motor is one I see here. The fuel line from the factory, for a reason, comes up from the front of the motor, where it is a little cooler. The same for your after market electric fuel pump, with the lines being close to the muffler. I would install that pump closer to the tank, away from any heat source. The biggest issue is the fuel you are using. Winterized fuel, which is what is being used now, all over, including Florida, where I'm at, vaporizes easy. Carburetor cars have a problem with it, fuel injected ones do not, because the fuel in them are pushed thru the lines and not drawn. BTW, I'm talking from experience here, I also "HAD" that problem. You can also go to non-ethanol fuel, which may help.