Vapor lock

K

kingskid

Member
I know this has been asked probably 100's of time. Is there a cure for this problem. I have a59ab in my 47 with two stromberg 97's. Very hard to start after it has been run. Thanks in advance.
 
Use pure gas, no ethanol, it helps. Do you have dual exhaust? I ask becuase if you do the left side exhaust will pre-heat your fuel in the line along the frame. This make the situation worse. You can also buy a phenolic spacer that is placed beween the carbureator base and the intake the will also help. You can also insulate the line bewteen the fuel pump and the carburetor.

Todays fuels are just bad.
 
kingskid. Look at the link that 19Fordy attached. I have no issues with my stock '46 Coupe starting/running, since I had; Skip Haney rebuild my coil, Charley Schwendler rebuild my carb and fuel pump, Bubba did my distributer, put on a "Trashcan" condenser from Tubman, and installed the correct battery/ground cables for 6 volt system. These people do extremely fine work, and the prices are reasonable and worth knowing the engine will always start.
 
SO, my question is....based on " Very hard to start after its been run." HOW do you know its a "vapor Lock" situation?? OR put another way, are you sure you don't have another issue OTHER than vapor lock??
 
If you don't have one, install an electric fuel pump. Turn it on just before you restart the car. Once the car is running well again, turn it off.
 

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Thanks for all the help. It starts right up when cold. I do run an electric F/P. I Energize it when it has been run, but does not seem too help. If I hold it to the floor it starts and runs fine after it clears.
 
Just want to also mention that vapor lock is not a carburetor issue. It's a lack of getting fuel to the carburetor because of heat on fuel lines and/or fuel pump when the gas boils and forms a vapor pocket of air.
A phenolic spacer under the carb will help keep the fuel from boiling in the carb after a hot shutdown. Especially fuel with ethanol in it.

Sal
 
I had the same problem with my 81a with dual 97s. It is not the gasoline. And your ignition must be okay because it starts cold. I put cupped core plugs in the heat risers in the block and I put 4 carb to manifold gaskets under each carb - need longer studs. This will make it a fair weather car - might as well park it in the garage when the temp is at 55 deg F or less. I am at about 600 ft elevation and I use 45 mains (stock) and 71 power valves in the carbs.
As a side note I have cleaned and tightened all starting and ignition connections to avoid voltage drop, but I think your problem is the carbs receiving toooo much heat. Blocking the heat on my 81a now gives instant starts when hot, even with the ethanol gas.
 
I had the same problem with my 81a with dual 97s. It is not the gasoline. And your ignition must be okay because it starts cold. I put cupped core plugs in the heat risers in the block and I put 4 carb to manifold gaskets under each carb - need longer studs. This will make it a fair weather car - might as well park it in the garage when the temp is at 55 deg F or less. I am at about 600 ft elevation and I use 45 mains (stock) and 71 power valves in the carbs.
As a side note I have cleaned and tightened all starting and ignition connections to avoid voltage drop, but I think your problem is the carbs receiving toooo much heat. Blocking the heat on my 81a now gives instant starts when hot, even with the ethanol gas.
 
scicala said:
Just want to also mention that vapor lock is not a carburetor issue. It's a lack of getting fuel to the carburetor because of heat on fuel lines and/or fuel pump when the gas boils and forms a vapor pocket of air.
A phenolic spacer under the carb will help keep the fuel from boiling in the carb after a hot shutdown. Especially fuel with ethanol in it.

Sal
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Just a quick follow up to Sal. When I am out for a drive and stop at a gas station for a fill up, the time it takes, allows the gas to boil and create the vapor lock. Hence, I turn on the fuel pump and it clears the vapor pocket. It usually takes a mile or two to get the car running smoothly again. Once it does, I turn off the pump.
 
Merc Cruzer said:
Just a quick follow up to Sal. When I am out for a drive and stop at a gas station for a fill up, the time it takes, allows the gas to boil and create the vapor lock. Hence, I turn on the fuel pump and it clears the vapor pocket. It usually takes a mile or two to get the car running smoothly again. Once it does, I turn off the pump.
Click to expand...

What's odd is, when I was a kid driving Y Block cars (mainly a '55 Mercury), I never experienced vapor lock even on hot days.
I attribute it to ethanol in the fuel these days.

Sal
 
scicala said:
What's odd is, when I was a kid driving Y Block cars (mainly a '55 Mercury), I never experienced vapor lock even on hot days.
I attribute it to ethanol in the fuel these days.

Sal
Click to expand...

Same here, my first car was a 50 Ford that I paid $15 for. I knew nothing about flatheads or vapor lock, and never had an issue. I still miss that car. That was 58 years ago. Now I have rebuilt my 53' Merc from bumper to bumper and before I figured it out, it actually left me in my driveway once.

Either ignorance is bliss or too much education is dangerous.
 
kingskid said:
Thanks for all the help. It starts right up when cold. I do run an electric F/P. I Energize it when it has been run, but does not seem to help. If I hold it to the floor it starts and runs fine after it clears.
Click to expand...
Lots of bad advice being given here, because people are not absorbing the original poster’s particular symptoms. Read the last sentence in his post above. Sounds to me like a flooding issue, not lack of fuel, not poor ignition.
 
JayChicago said:
Lots of bad advice being given here, because people are not absorbing the original poster’s particular symptoms. Read the last sentence in his post above. Sounds to me like a flooding issue, not lack of fuel, not poor ignition.
Click to expand...
NOTE post#5
ALSO Post#9 "IF i hold it to the floor, its starts and runs fine after it clears"



Jay, I suspected that the fuel was draining from the bowls at shut down......The cause I am not educated enough to know BUT I figure that is a strong possibility....which I believe the power valves to "maybe" have some function in/maybe stuck float valves??? I've been following, waiting for what I suspected the "educated" response!!!
 
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rockfla said:
NOTE post#5
ALSO Post#9 "IF i hold it to the floor, its starts and runs fine after it clears"



Jay, I suspected that the fuel was draining from the bowls at shut down......The cause I am not educated enough to know BUT I figure that is a strong possibility....which I believe the power valves to "maybe" have some function in/maybe stuck float valves??? I've been following, waiting for what I suspected the "educated" response!!!
Click to expand...

He could have a leaking power valve that floods the engine when it's not running. That will cause a rich fuel situtation and bad idle at start up.

We've all givin him sound advice. It's hard to diagnose a car on a computer 1000 miles away.
 
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