Topic: Vapor Lock?
in Forum: C3 Fuel, Emission Control, and Exhaust Systems
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Today it was about 90 degrees with a good dose of humidity.
I drove my Corvette around town for about 10 minutes. It ran well and the temp gauge never went above 220 degrees.
When I got back home I parked it for about 10 minutes with the hood up. ( I always open the hood to let out excess heat after driving it.)
My son's friend needed a ride home, so I took him in the Corvette.
While on that short ride I never went over 35 MPH as we were on residential streets. Just before getting the kid home I let off the gas and the motor stalled.
I opened the hood and smelled a good amount of gasoline fumes. No gasoline or other fluids were dripping from the motor on to the ground.
I let it sit with the hood open for about 10 minutes. No more gas fumes.
Then it started back up just fine and ran good after that. The temp gauge remained below 220 degrees the whole time.
What does this sound like? Was it "Vapor Lock"?
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I've been having a bad go of it this week as well. Mine cuts out at heavy throttle. I live at 5000 feet above sea level and it has been 100 degrees. Doesn't do this at all in milder temperatures.
Could it be that the gasoline actually starts to boil before it gets to the carb? I know the motor was throwing off some serious heat.
Is the air temp. under the hood so hot that the car breaths in hotter than normal air & this stall was caused by it?
I'm just diggin' for some ideas.
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Vapor lock is indeed caused by fuel boiling in the line...it creates a vapor as the liquid fuel boils in the fuel line, which doesn't allow any more liquid fuel to pass.
Some folks scoff at the old "wooden clothes pin on the fuel line" thing, but it does work. The wood basically soaks up the heat from the line, keeping the line from getting hot enough to cause the vapor lock. I've seen guys with Mid-Years have 10-15 clothes-pins on their fuel lines when driving on a road trip...
I had a 69 Pontiac Bonneville/428 a long time ago. A couple of friends and I decided to take a road trip down the Pasadena, Tx, to go to the new Gilly's club.(This was right after the Urpin Cowboy movie came out
)
On the way home, the old Pont started the dreaded vapor lock. We were all tired...and maybe just a wee bit sloshed, and not really in the mood for car troubles.
Not having a stash of clothes-pins, I wound up soaking some shop towels in...er..well, the only liquid we had at the time....beer! I wrapped the rags around the metal fuel line, and we kept on trucking. Made it back home in just enough time to go to werk... 
The beer-soaked rags cooled the metal line enough to kill the vapor lock...
Adams' Apple 2008-07-17 21:53:08
Some folks scoff at the old "wooden clothes pin on the fuel line" thing, but it does work. The wood basically soaks up the heat from the line, keeping the line from getting hot enough to cause the vapor lock. I've seen guys with Mid-Years have 10-15 clothes-pins on their fuel lines when driving on a road trip...
I had a 69 Pontiac Bonneville/428 a long time ago. A couple of friends and I decided to take a road trip down the Pasadena, Tx, to go to the new Gilly's club.(This was right after the Urpin Cowboy movie came out
)
On the way home, the old Pont started the dreaded vapor lock. We were all tired...and maybe just a wee bit sloshed, and not really in the mood for car troubles.
Not having a stash of clothes-pins, I wound up soaking some shop towels in...er..well, the only liquid we had at the time....beer!
I wrapped the rags around the metal fuel line, and we kept on trucking. Made it back home in just enough time to go to werk...
The beer-soaked rags cooled the metal line enough to kill the vapor lock...
Joel Adams
C3VR Lifetime Member #56 
My Link 
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Hey Kevin, do you have headers on your car? If you do make sure the fuel line isn't too close to the header.
PM sent,
Dave
Lifetime Member #116
Dave's '82 
20111115155328r.jpg)
Should it really be running up near 220?? Since I did a new rad and finally got the air pocket out (drilled 1/8" hole in thermostat which I learned here) mine never gets near that 200 mark. Out yesterday for an hour or so in close to 90 degree weather.
I will have to remember that one Joel.. Make sure i buy a beer for the vette! 
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Vapor lock is not totally caused by heat alone...heat is just the major factor.
The volatility of the fuel has a role in the phenomenon, also. I think Ken has posted a really good explanation of it in another thread somewhere.
The volatility of the fuel has a role in the phenomenon, also. I think Ken has posted a really good explanation of it in another thread somewhere.
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Adam, would you put the clothes pins on the fuel line between the tank and the pump, or between the pump and the carb, or both?
Thanks,
Matt
Sorry Joel, your name is not Adam.
Matt
in Forum: C3 Fuel, Emission Control, and Exhaust Systems
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