Vapor Lock Remedy/ Advice

[Charlied]

Had car out to local cruise in Saturday. Cold start fine, drove about 30 minutes to event, arriving @ 8:30. Decided to leave @ noon. Crank and crank no start. Carb getting no fuel, had more than 1/2 tank. Pulled fuel filter, clean.fuel pump working. Put one short shot of starting fluid in carb, started.
I never had this issue before and don’t want to experience it again. Car is 400 4bbl. Carter Thermoquad rebuilt early spring performs well, mechanical fuel pump.
Any advice, install electric fuel pump?

Thanks
Charlie D

 

[68BabyBlue]

I had (have) the same problem with stock GTXs that had the factory vapor separator removed, and the return line plugged off. This became common when the supply of factory vapor separators dried up. I kept an inventory of NOS separators from back in the day. Put a separator back in the the Track Pak car I just sold, and problem solved. Need to do the same with my current Hemi car, have the identical problem. Short term fix is that shot to the carb. Gas will work as well as starting fluid. Is your car plumbed with a return line?

 

[moes]

the first thing I would try is install Phenolic spacer to separate the carb from the hot intake. You will need longer carb studs if you use one.

 

[SuperRatBastid]

Block the heat crossover on the intake. It’s not vapor lock. The manifold gets so hot it’s boiling the fuel right out of the carb.

 

[69a100]

It’s not vapor lock. The manifold gets so hot it’s boiling the fuel right out of the carb.

Your comment makes NO sense! When liquids boil they turn to a vapor/steam, how is that NOT vapor lock?

 

[R413]

Your comment makes NO sense! When liquids boil they turn to a vapor/steam, how is that NOT vapor lock?

No it is not. Vapor lock happens inside the fuel line and no liquid will flow.

Use ethanol free gasoline. Really helps this problem. There are 6 places in Woodstock, GA to get it.

https://www.pure-gas.org/index.jsp?stateprov=GA

 

[69a100]

No it is not. Vapor lock happens inside the fuel line and no liquid will flow.

Use ethanol free gasoline. Really helps this problem. There are 6 places in Woodstock, GA to get it.

https://www.pure-gas.org/index.jsp?stateprov=GA

WTFever!

 

[GrabberOrange69]

The ethanol free gas works for me too. Unfortunately, I pay ~$1.50/gal more for it, but I have had far fewer carb problems once I switched.

 

[R413]

Block the heat crossover on the intake. It’s not vapor lock. The manifold gets so hot it’s boiling the fuel right out of the carb.

Your comment makes NO sense! When liquids boil they turn to a vapor/steam, how is that NOT vapor lock?

The way you know this isn’t vapor lock? This fuel boiling out the carb into the intake crap NEVER happened in the 70’s, but “vapor lock” was real and happened plenty back then.

WT fever

 

[dodgeboy440]

Your comment makes NO sense! When liquids boil they turn to a vapor/steam, how is that NOT vapor lock?

FYI…..

With the mandated “ E” blending

of fuels causes …..

increased fuel system corrosion

Increased evaporation of fuel

drivability issues for classic cars

I’m confident we’ve all had our
Cars vapor lock in traffic & high temps in the past.
With the blended fuels it exacerbates the issue .

In my opinion you need to be proactive with fuel system
Construction & maintenance if you’re going to drive you’re
Mod-Rod & enjoy it .

Means … Thermal Protection
Means … carbs tuned & using correct gasketing / pumps compatible with E blends …

It’s Up 2 U!

Mopar2ya !!

John

 

[Carcinogen]

Same problem on 71 Satellite with 440 and headers, not enough airflow around fuel pump.

Non alcohol fuel helps a lot, costs a lot more too. Have taken hood off which helps along with non-metal spacer. Still have problems in 90+ days

Going to try electric fuel pump with pressure regulator with return so there is fuel flowing back to tank next.

By just having gas flow from mechanical fuel pump dead ending at carb allows fuel to get hot from not flowing fast enough.

 

[68BabyBlue]

Baby Blue has the spacer, electric fuel pump, factory vapor separator, insulation around all fuel lines within a foot of the engine block, but still has the the intake manifold hot spot. Car starts as reliably as my Lexus in hot weather. Modern gas has not been an issue, no question in my mind the mods and factory separator work well, having driven the car since 1983. Vapor lock was an issue with all my early slant six cars back in the 70s, even with the good leaded fuel of the era, I was pleasantly surprised when my first GTX with the factory vapor separator didn't have the problem.

 

[Charlied]

I had (have) the same problem with stock GTXs that had the factory vapor separator removed, and the return line plugged off. This became common when the supply of factory vapor separators dried up. I kept an inventory of NOS separators from back in the day. Put a separator back in the the Track Pak car I just sold, and problem solved. Need to do the same with my current Hemi car, have the identical problem. Short term fix is that shot to the carb. Gas will work as well as starting fluid. Is your car plumbed with a return line?

 

[Charlied]

Unfortunately it doesn’t.

I had (have) the same problem with stock GTXs that had the factory vapor separator removed, and the return line plugged off. This became common when the supply of factory vapor separators dried up. I kept an inventory of NOS separators from back in the day. Put a separator back in the the Track Pak car I just sold, and problem solved. Need to do the same with my current Hemi car, have the identical problem. Short term fix is that shot to the carb. Gas will work as well as starting fluid. Is your car plumbed with a return line?

unfortunately my car 74 Satellite all original ( I’m original owner) doesn’t, never did . Would like to have it but don’t want to mess with tank.
Will put it ethanol free first, electric fuel pump difficult to install?
What’s mysterious is this never happened before and car was sitting for three hours.
Thanks

 

[Charlied]

The ethanol free gas works for me too. Unfortunately, I pay ~$1.50/gal more for it, but I have had far fewer carb problems once I switched.

For the amount I drive the car the cost of e free gas not an issue.

 

[GrabberOrange69]

For the amount I drive the car the cost of e free gas not an issue.

Just out of curiosity, what grade is available in your area? I have 2 places that sell 92 eFree. There are others that sell 87 eFree and I like that in the mowers as it doesn’t gum up in the off season.

 

[SuperRatBastid]

Your comment makes NO sense! When liquids boil they turn to a vapor/steam, how is that NOT vapor lock?

It makes perfect sense. Vapor lock occurs when the fuel boils in the fuel pump. That is the definition of vapor lock.

The OP is experiencing what happens when the intake manifold gets so hot the fuel in the bowls evaporates. It’s not vapor lock.

Just so I’m clear, vapor “lock” occurs when the fuel in the pump turns to a vapor and the pump can’t push that vapor to the carb.

So what I said is correct and makes perfect sense.

 

[68BabyBlue]

Another thought, trying to keep things simple, how old is the current fuel pump in your car? The ethanol may have messed it up. I installed new fuel pump when i did the vapor separator, i was concerned high ethanol gas car had used in Iowa had compromised it. Problem solved, but i can’t say for sure which component, or both was the cure.

 

[Charlied]

The ethanol free gas works for me too. Unfortunately, I pay ~$1.50/gal more for it, but I have had far fewer carb problems once I switched.

Another thought, trying to keep things simple, how old is the current fuel pump in your car? The ethanol may have messed it up. I installed new fuel pump when i did the vapor separator, i was concerned high ethanol gas car had used in Iowa had compromised it. Problem solved, but i can’t say for sure which component, or both was the cure.

fuel pump maybe 2 yrs old, when I pulled the filter and hit the key fuel gushed, filter was clear as well. Question, would adding Sta bil help with gas in tank which is 3/4 full . will switch e free after that.
Thanks

 

[69a100]

It makes perfect sense. Vapor lock occurs when the fuel boils in the fuel pump. That is the definition of vapor lock.
The OP is experiencing what happens when the intake manifold gets so hot the fuel in the bowls evaporates. It’s not vapor lock.
Just so I’m clear, vapor “lock” occurs when the fuel in the pump turns to a vapor and the pump can’t push that vapor to the carb.
So what I said is correct and makes perfect sense.

I sure hope you're not that fat, ugly, self centered, ego centric, narcissist that has that stupid *** show called Graveyard Trash? BTW, vapor lock can happen anywhere in a fuel system, not just the manifold or pump as you say!!!!