Vapor lock- additive?

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Syleng1

Syleng1

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With all the talk on utube and on here and other sites about vapor lock. Now the info about how the fuel is separating into parts and evaporation is taking place due to the new fuel has no additives to prevent the lighter or easily boiled off parts from happening since new cars are closed systems.

My question is: is there an additive that prevents this evaporation from happening? I’m being told that some fuel is evaporating in less then 2-3 days and what’s left in the tank is not enough to start the car, this is causing hard starting, runs like garbage and vapor lock.

Now you either have experienced vapor lock or you have not. If you have, it stinks, but adding a return line and a 3 nipple filter may be the way - thanks to UTG and DDG for that info… but is there anything you can buy to add to the fuel at fill up to slow down this process?
Syleng1
 
Syleng1 said:
With all the talk on utube and on here and other sites about vapor lock. Now the info about how the fuel is separating into parts and evaporation is taking place due to the new fuel has no additives to prevent the lighter or easily boiled off parts from happening since new cars are closed systems.

My question is: is there an additive that prevents this evaporation from happening? I’m being told that some fuel is evaporating in less then 2-3 days and what’s left in the tank is not enough to start the car, this is causing hard starting, runs like garbage and vapor lock.

Now you either have experienced vapor lock or you have not. If you have, it stinks, but adding a return line and a 3 nipple filter may be the way - thanks to UTG and DDG for that info… but is there anything you can buy to add to the fuel at fill up to slow down this process?
Syleng1
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Not that I have heard of. Most of the issues are fuel percolating and hot soak. Not many of our cars run like crap and stall because of vapor lock.
 
I've always used Lucas ethanol treatment in my Duster and D200, they run a bit smoother with it and aren't as prone to boiling the gas in the carb on hot days in traffic. I drive them 1-2 times a week though and they generally get filled up once or maybe twice a month. I also use it in the gas for my riding mower and that stuff lasts several months in a sealed container, just regular 87-octane E-10 pump gas.

Sta-bil 360 seems to work too, I haven't been seeing the Lucas as much in stores lately I might order some off the web.
 
I daily drive my dart in the LA area. I run a carb spacer and drive enough that the stuff in the tank never goes bad (fill up whole tank with 87E10 every 7-10 days). I have not had any problems with vapor lock or percolation with this setup.
 
Most modern issues with vapor lock are due to ethanol content. If you try some of the ethanol additives, you might have success. But I'll say this yet again. REAL vapor lock is extremely rare these days, because of all the additive packages already in gasoline.
 
I solve the shutoff/hot soak/fuel boil/won't restart issue with a pretty basic solution. To shut the car off, I first turn the fuel pump off and let the engine empty the carb until it stalls (maybe 30 seconds or so). With no fuel in the bowls, you get no vapor/boiling during the hot soak and thus no vapor lock or rich restart disasters. When it's time to start, flip the fuel pump on to refill the bowls in about 3-4 seconds then hit the key and the car(s) fire right off. Simple, old school hack!
 
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Well most of us are running mechanical pumps…

And mechanical pumps are usually worse off in this metric since they put way more heat into the fuel than an electric pump.

But to be honest I don’t think it’s a big problem either way. If you have an intake with the exhaust crossover blocked and are running a carb spacer the fuel stays pretty cold. I always have fuel in the bowls of my aluminum holley for up to a week
 
I have beeb using Driven's Carb Defender to deal with other ethanol issues for many years. (Summit, Jegs, Amazon) Solved the carb corrosion issues. Ethanol attracts and bonds to water in the air and in your fuel. My understanding is that the ethanol actually evaporates less readily than the modern gas. In the fuel bowl the gas goes away leaving the water laden ethanol behind, hence the carb corrosion issue especially on cars not driven all the time. I put in a small vane type fuel pump in line back toward the tank. Before starting I run the fuel pump far the count of 20. This fills the fuel bowl in the carb and the car starts much more easily. That's all I use the electric fuel pump for. The mechanical pump pulls gas through the vane style pump without any problem.
 
The best vapour lock additive is to get rid of the mech fuel pump & use a Carter elec pump mounted near the tank.
 
Thanks for the replies everyone.

I’ve been using a product called K1000 for both diesel and gas. (Not the same - one version for diesel and one version for gas) $25 per quart it’s kinda pricey. The diesel stuff basically keep the gelling down in the winter and helps displace water in my 500 gallon storage tank here on the farm. My Demon and barracuda I dump a little bit in on every fill up and they are good. I must be in a loop on utube or something as I roll past video after video of vapor lock style issues. It just got me thinking- if you can add something to stop this percolation from happening is it the same stuff as what you add to a can to store fuel.
 
Lord Sparky said:
Some of us are too young to remember all the starting problems these cars had when they were new. Everyone had to be a mechanic.
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You had to at the very least know to hold the gas pedal open when starting a hot engine. Now a lot people don't know how to drive carbureted engines anymore.
 
Syleng1 said:
Thanks for the replies everyone.

I’ve been using a product called K1000 for both diesel and gas. (Not the same - one version for diesel and one version for gas) $25 per quart it’s kinda pricey. The diesel stuff basically keep the gelling down in the winter and helps displace water in my 500 gallon storage tank here on the farm. My Demon and barracuda I dump a little bit in on every fill up and they are good. I must be in a loop on utube or something as I roll past video after video of vapor lock style issues. It just got me thinking- if you can add something to stop this percolation from happening is it the same stuff as what you add to a can to store fuel.
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Are you 100% SURE your problem is vapor lock? You can use the old clothespin trick to diagnose it. That will tell you real quick.
 
Syleng1 said:
if you have experienced vapor lock -adding a return line and a 3 nipple filter may be the way - thanks to UTG and DDG for that info…
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Would This solution bleed off half of your available pressure tho? it seems that just maybe your 5-6psi mechanical pump wouldn't be able to put 5 psi to your carb anymore w/ a return line.
Is This a thing?
 
eekvonzipper said:
Would This solution bleed off half of your available pressure tho? it seems that just maybe your 5-6psi mechanical pump wouldn't be able to put 5 psi to your carb anymore w/ a return line.
Is This a thing?
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Not half. But it will bleed off some. That is, as long as you use a bypass regulator for the return orifice, OR use a fuel filter with a metered orifice return nipple. If you simply plumb in a straight return, then yeah, your fuel pressure will drop dramatically.
 
RustyRatRod said:
Are you 100% SURE your problem is vapor lock? You can use the old clothespin trick to diagnose it. That will tell you real quick.
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Not saying I’ve got vapor lock at all. I’m just reading the tea leaves here Rusty. I’m stuck in a loop on Boob tube that almost every car video that pops up lately is about vapor lock. The why and how but other than a mechanical fix- nobody is addressing how to fix by adding an additive, like the fuel companies did back when we were kids. 60’s and 70’s cars until
Charcoal canister emissions never had a return line. You vented thru the gas cap and did not deal with vapor lock. It’s only because of modern fuel do we deal with it. The quick burn stuff evaporates easily from what I am reading. How do we keep that from happening without a closed loop system. I’m not sure if I’m not dealing with it because I’m running 3/8” metal line to the big Carter fuel pump or my current additive or **** luck.
 
Syleng1 said:
Not saying I’ve got vapor lock at all. I’m just reading the tea leaves here Rusty. I’m stuck in a loop on Boob tube that almost every car video that pops up lately is about vapor lock. The why and how but other than a mechanical fix- nobody is addressing how to fix by adding an additive, like the fuel companies did back when we were kids. 60’s and 70’s cars until
Charcoal canister emissions never had a return line. You vented thru the gas cap and did not deal with vapor lock. It’s only because of modern fuel do we deal with it. The quick burn stuff evaporates easily from what I am reading. How do we keep that from happening without a closed loop system. I’m not sure if I’m not dealing with it because I’m running 3/8” metal line to the big Carter fuel pump or my current additive or **** luck.
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Get a bunch of clothes pins and clamp them on all of the available hard line under the hood. If the problem goes away, you have vapor lock. It's cheesy but it's a good diagnostic tool.
 
Syleng1 said:
Not saying I’ve got vapor lock at all. I’m just reading the tea leaves here Rusty. I’m stuck in a loop on Boob tube that almost every car video that pops up lately is about vapor lock. The why and how but other than a mechanical fix- nobody is addressing how to fix by adding an additive, like the fuel companies did back when we were kids. 60’s and 70’s cars until
Charcoal canister emissions never had a return line. You vented thru the gas cap and did not deal with vapor lock. It’s only because of modern fuel do we deal with it. The quick burn stuff evaporates easily from what I am reading. How do we keep that from happening without a closed loop system. I’m not sure if I’m not dealing with it because I’m running 3/8” metal line to the big Carter fuel pump or my current additive or **** luck.
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Modern (if that’s what it really is because we are stuck with it) pump fuel has a fairly slow burn rate and it vaporizes very poorly.

Pour a cup of pump gas on the floor and watch it. Then do the same with a race fuel and watch the difference. If you really want to check things out, do the same thing with methanol.

Because the fuel is under much higher pressures with an injector the fuel is blended for that rather than the 7 psi that carbs use.

That’s why today it’s harder to get a cold air intake to function. Today’s fuel needs more heat to get it vaporized and a cold intake (like an air gap or tunnel ram) doesn’t have enough heat to do it.

I’m guessing that’s one reason why I think you can run more compression on pump gas than once believed.
 
Syleng1 said:
Not saying I’ve got vapor lock at all. I’m just reading the tea leaves here Rusty. I’m stuck in a loop on Boob tube that almost every car video that pops up lately is about vapor lock. The why and how but other than a mechanical fix- nobody is addressing how to fix by adding an additive, like the fuel companies did back when we were kids. 60’s and 70’s cars until
Charcoal canister emissions never had a return line. You vented thru the gas cap and did not deal with vapor lock. It’s only because of modern fuel do we deal with it. The quick burn stuff evaporates easily from what I am reading. How do we keep that from happening without a closed loop system. I’m not sure if I’m not dealing with it because I’m running 3/8” metal line to the big Carter fuel pump or my current additive or **** luck.
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YouTube is really annoying about that, they'll keep feeding you videos on the same stuff based on your watch history. If you go and delete all your watch history the same stuff will stop popping up in your recommended videos. Just another way they keep us glued to our screens and watching their ads.
 
IF the car is actually having a problem,
A. Buy your hot weather fuel after May 1st. For any car that hasn't rerouted line or exhaust, pretty much done.
www.gasbuddy.com

The Difference Between Summer-Blend and Winter-Blend Gasoline

We’re talking about the cost differences between summer and winter gasoline along with how to save money on your fill-up.
www.gasbuddy.com www.gasbuddy.com

B. Anyone saying there is one answer to vapor lock hasn't even begun to know what they are talking about.
First thing is to figure out where in the line its occuring, and under what conditions.
If the vapor lock occurs before the pump is different than if it occurs in the feed to the carb. If it happens while running is different than flooding after shut down - which isn't really vapor lock - and one can use one of the factory solutions of incorporating a tiny relief.
If the fuel is significantly vaporizing in the carb bowl - that's not vapor lock either. Fuel still gets into the bowl in liquid state.
 
Mattax said:
IF the car is actually having a problem,
A. Buy your hot weather fuel after May 1st. For any car that hasn't rerouted line or exhaust, pretty much done.
www.gasbuddy.com

The Difference Between Summer-Blend and Winter-Blend Gasoline

We’re talking about the cost differences between summer and winter gasoline along with how to save money on your fill-up.
www.gasbuddy.com www.gasbuddy.com

B. Anyone saying there is one answer to vapor lock hasn't even begun to know what they are talking about.
First thing is to figure out where in the line its occuring, and under what conditions.
If the vapor lock occurs before the pump is different than if it occurs in the feed to the carb. If it happens while running is different than flooding after shut down - which isn't really vapor lock - and one can use one of the factory solutions of incorporating a tiny relief.
If the fuel is significantly vaporizing in the carb bowl - that's not vapor lock either. Fuel still gets into the bowl in liquid state.
Click to expand...

you're right you know..jpg
 
An electric pump does fix v/lock. Modern cars use elec pumps.....& the same fuel.....& they don't get v/lock. Pump needs to be mounted near the tank.
 
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