So I have been battling a vapor lock issue with my 340 Challenger for about a year now. The car does fine until I stop for awhile - then once restarted the car will get a few miles down the road and sputter - sputter until it stalls.

Its a fairly stock setup - stock 340 longblock, performer intake, eddy carb, mopar ignition.

Some things I have tried so far:
-1" plastic carb spacer
-wrapped all the fuel lines underhood with heat wrap
-installed aluminum radiator
-replaced fuel pump with Edelbrock mechanical

The car runs great otherwise but its so frustrating when it sputters to a stop. I can usually dump some gas down the carb and limp home but its sure getting old.

I'm thinking about installing an electric fan next and set it up on a thermostat to run when parked until it cools down. As the temp usually jumps to around 210-220 when parked.
Or
I saw a post about a 3 port filter and run one port as a return line to the gas tank.

Do you guys have any ideas?

The return style fuel system is a great idea. It has double benefit. Fuel circulates through the system to keep things cooler plus the return will take bubbles back to the tank.

The 3 prong fuel filter is the easiest way to get it done. Combine it with a 1/4" return line from in-line tubes and a pickup with return port.

Most gas around now is cut with 10% alcohol. The downsides of this are: fuel mileage is worse than straight gas, prices don't seem to be any cheaper, and alcohol boils easier than straight gas (hence easier vapor lock). So try and shop around and stay away from E-10. I'm fighting the same problem on my 360. I'm going to look into rigging some kind of heat shield between the fuel pump and the exhaust manifold to reduce the temperature of the pump.

I doubt its vapor lock.

I'm pretty sure its vapor lock you can hear a sucking sound from fuel line when it happens and the carb is bone dry.

It seems to only happen now on warm days - over 80.

Might be vapor lock, install an electric fuel pump, none of the other stuff is going to make a difference if it is vapor lock. But I'm thinking something is gettin heat soaked i.e. coil, ballast resistor, alternator. I don't undertand the pouring gasoline down the carb to get home, that does sound like vapor lock. Go to walmart and buy a can of dust off, when it happens again spray it on the fuel lines. It will supercool the lines and breakup the vapor lock.

reroute the fuel lines may help.

My set up is elsctric, but as an example...
I have my supply line to the regulator run outside the frame, throught the wheel well, to the regualtor, then braided line directly across from the regulator to the carb.(stock line from tank is inside the frame, and ends up right next to the headers if you are running them)

Wrapping the stock lines, that run behind the alternator, against the head, won't help you much to reduce transfer either.

Run the outlet line from the pump back out to the the inner fender away from the engine, up the inner fender and across to the motor up higher, above the valve cover.

The mechanical pump is one of the biggest issues here. It directly transfers engine heat to the fuel. Once you stop, and it get's hot, it is very difficult to cool it down.

I suppose you could try to go old school and install a cool can too. They did work.

New fuel pump huh? I had a 69 GTX that would die after a hot soak. One time I trired pouring cold water on the pump and it started. Also check all rubber lines especially at the tank. A little crack might not even leak but it can suck air and cause nightmares. A clogged up sock or in tank filter can cause trouble too.

IT IS TIME .....

..... for a fuel pressure CHECK

Return style regulator and an electric pump will solve your issues if it actually is a vapor lock problem.

People complain about the quality of todays gasoline, but few know what makes it different to the gas available up until the mid 1970s.
Todays gasoline has been formulated to evaporate quicker. This isn't a problem for fuel injected cars with a fuel return system. New cars are designed to keep the fuel in a loop, Whatever isn't used is sent back to the tank. This keeps the fuel in liquid form and cooler as well. Our old cars store fuel in the carburetor which sits over a massive stove. Todays gas evaporates quicker and boils at a lower point than ever before. Some guys use a 1/4 inch gasket under the carb, maybe even a heat shield. The methods you tried are usually successful in most cases. There was an article in Mopar Action some time ago where they modified a Holley carb to run a return line to the tank. Maybe their website has it somewhere.

The accelerator pump is not squirting when it stalls because there's no gas getting to the carb anymore. Since there's no gas getting in there if I pour a splash of gas down the carb it'll fire up and usually get enough gas flowing to make it home. I wish I would have just put an electric pump on it at this point instead of the Eddy but since it a street car I thought it would be more reliable.

I like the freeze the line idea and I guess the cool can would be an easy idea too.

I have swapped ignition boxes and the coil as well which didn't help.

I had the same problem on an 83 Fifth Ave about 10 years ago. I read somewhere at that time that running the stock style fuel pump (or an electric pump near the engine), pulling gas from the tank, causes the gas in the line between the tank and the pump to be under lower pressure since it's being sucked to the engine. This will create a sort of vacuum situation in the line, and promote vapor lock. They recomended installing an electric pump near the tank so that you are pressurizing the line, and then any bubbles or boiling in the line will be forced on through to the carb. The carb can handle the bubbles - they just go out the vent, so as long as you have more fuel being forced into the carb behind the bubbles, you are fine. Also, fuel under pressure has a higher boiling point (the more you increase the pressure of a liquid, the higher the boiling point), so that will also help reduce any vapor lock. I installed an electric pump about 12 inches from my fuel tank, and never had a probelm again.

You need to install a fuel pressure guage before the carb to help see what's going on. Check any hoses in the fuel line from tank to carb especially the short hose coming off the tank. A small crack in a hose can suck air but not leak fuel.

So maybe one of these back by the gas tank would help.

http://www.jegs.com/i/Mr-Gasket/720/42S/10002/-1?parentProductId=1196572

I'm going to drop a 160 thermostat in there too because the car seems to hold alot of underhood heat.

do yourself a favor and install, a oil cooler also. http://www.summitracing.com/parts/FMS-M-6642-S101/
almost every modern car has a oil cooler for a reason. with cooler oil you will be surprised how much cooler your car runs.

Well changing the thermostat didn't help as the car left my wife standed on her way home work Friday. So when I went and picked her up - I decided to change the primary jets - richened it up a couple. Next I had to get gas flowing again but when I unhooked the fuel line from the pump no gas flowed, not even a trickle. So I jacked up the rear and finally got some gas down the line and was able to prime the pump. Hooked everything back up and made it home. At home I loosened the fuel line at the carb and it sounded like an air compressor hose. A bunch of air came out but very little gas??? Anyway I replaced the line between the pump (rubber pushlock hose) and carb with one of jegs built in filter units, added a fuel pressure gauge and the rest is now stainless braided line.

The other thing I noticed was the factory clutch fan seemed very, very loose. So I replaced it with a flexfan. The engine bay stays Sooo much cooler now. The temp gauge shows about the same but I can actually touch the radiator and intake without scalding myself. The fuel pump and lines even feel cool now.

Anyway I drove about 50 miles stopping and starting today without any trouble. So hopefully its fianlly fixed. It looks like I had a combination of problems - fan clutch worn out, carb set too lean and poor fuel line material/routing.

I think momma wants to take it to the track Wednesday and see what it'll run now. Ran 13.60's last year. If it runs okay she'll probably go ahead and race it at the Classic since its almost the same cost as spectating all weekend.

Thanks Guys!