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Ways to fix vapor lock without a return line

mquinn66

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Hello b body folks, I have a 66 charger that im just getting back on the road after 20 plus years. I went out for the longest drive so far and i think I have a vapor lock issue. Is there a way to fix this without adding a return line to the tank. My tank is a new stainless steel without return line. So im wondering what my options are to fix this vapor lock situation. Should i only run non ethanol? Should i insulate the line where its close to heat? Should i just add an electric pump? I never had this problem back in the 90s when it was last on the road.
 
heat shield under the carb?
 
Do All the things suggested. I use an electric pump with my manual pump, just to get fuel into the carb after its been sitting.
 
Agree with all the answers above, but modern gas doesn't have the additives that prevent the gas from boiling, a return line will cool down the carb bowl with cool gas, the way u see it the return line is the best solution.
 
Did you visually see if you had a pump shot from the accelerator pump?
Make sure the heat riser valve is not stuck shut or partially stuck.
Consider an intake valley plate with the heat crossover blocked.
Also make sure you have spark in the cranking position when this occurs.
I've never had a vapor lock problem on mine yet I think my brother had this a little on his 67 Plymouth.
Just some ideas.
 
Heat shields under the carb can delay vapor lock, but may not solve it. Better to remove the issue rather then just delay the issue, IMHO. As Don Frelier suggests, blocking the crossover and ensuring the heat riser is not stuck is very helpful to keeping the fuel in the carburetor cool.

One other thing to check as well: I have seen cars where the fuel line is very close to hot surfaces, so make sure the fuel line is not touching anything. Invest some time in plumbing a hard line from the fuel pump to the carburetor where it is hanging in space everywhere. Also check other areas and make sure the fuel line is not near a header pipe or exhaust component.

Good Luck!
 
& that's the same reason (one of them anyway)
why even if you use an electric fuel pump
you should use a by-pass style fuel regulator too

the constant movement of the fuel, helps/keeps it cooler,
you can set the fuel flowing PSI better too, no spikes
& helps to keep the pump cooler
maybe even a longer pump life
then deadheading it, with a static regulator (no fuel return/bypass)
like so many people like to do
especially on these performance engines
lost of underhood heat is generated,
even with blocked-off heat risers, alum heads. aftermarket alum. intakes etc.

the lines can (will) get hot, cooler fuel makes more HP too,
it atomizes better
I personally like to insulate the underhood fuel lines
at a min by the areas where they cross or are even near a heat source

look at all these old cars with steel/any metal lines
'open to heat soak' especially the way the factory routed them
right against the water ports in the intake (or heads in many cases)
&/or near/against the engine block, headers/iron manifolds,
by a radiator & rad. hose or even near/by the heater hose etc.

I hear it all the time,
(I know all the other lame reasons too)
But, but, but;
I never have that problem :blah::blah::blah:
until they do
When a once of prevention is worth a pound of cure...
why even chance, to have the problem

That's my thoughts/experiences
& I'm not going to debate any of it

carry on nothing to see here

Jack Webb as Joe Friday Dragnet -Just the facts Man-.png
 
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Could be other things at play.. How is the fuel line routed factory or custom over top of the exhaust? Stock fan and GOOD radiator or electric fan and a small block radiator with a Big block... What I am getting at is there may be other reasons it's boiling the fuel... What engine? Starting with blocking off the heat crossover is an easy thing to start with you can buy the valley pan gasket with out the crossover stamped out of it...
 
I've had good luck with fresh non oxy gas, and routing the fuel line away from metal. And as stated, make sure heat riser isn't stuck closed, this was in a 67 Charger. The next year, with old, stabilized gas, I could hear that boil in the carb till I got fresh fuel
 
You can drill a hole in the sending unit and solder in a piece of tubing.
JB weld would likely work as well.
Thats what i was thinking of doing just not real sure there is room to do it. I think i will buy a new sending unit and go that route.
 
I've had good luck with fresh non oxy gas, and routing the fuel line away from metal. And as stated, make sure heat riser isn't stuck closed, this was in a 67 Charger. The next year, with old, stabilized gas, I could hear that boil in the carb till I got fresh fuel
I dont have the factory steel lines out of the mechanical pump. I have rubber running up near the shock and over the valve cover and manifold. I do have the rubber wrapped with heat shield in that area though. I think i will plumb some ni-cop line in the factory path to see if that helps too.
 
I removed the diaphram from my gas cap to try and help it breathe. It only vents inward and everytime i take the cap off it has alot of pressure.
 
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