How Do I Cure Vapor Lock ??

Spanish Dave · Jun 8, 2005

I have just been on a 650 mile round trip and the car ran OK except when it was really hot ... stuck in traffic and waiting to take my turn at drag racing. The engine cut out on tickover then starter moter just clicked but didn't turn the engine ... (this was sorted by tapping the solenoid on the Summit mini starter) but the car would not fire up. I noticed the in-line fuel filter which is of the cheapo plastic variety, was empty of gas ... after the car was left for 10 mins or so it had filled itself up again. Is this *Vapor Lock* ?? and if so, how can I cure it?
Also any tips on making a cover for the starter to keep the heat out? Yes I know I can buy one from Summit for $25 or so but it costs me $30 handling plus the freight charges plus around $50 import charges plus duty here in Spain .... so you can see that I would rather *fabricate* something myself. Anyone done this .. or anyone got a kit that they could mail me ??

65ShelbyClone · Jun 8, 2005

Back in highschool I had a '65 notchback with an overheating problem and even here in CA's 100+ heat, it never vapor locked on me. It did the same thing you described, though, with the filter filling back up after cooling off. All my friends' cars did it too, but never vapor locked. Something to consider is an electric fan for when you're moving slowly. You might also look into a phenolic carb spacer to keep manifold heat from transferring to the carb itself. Also make sure your fuel line isnt near a heat source like headers.

hotrodnut · Jun 8, 2005

Man, it's been years since I've delt with vapor lock but the best I can suggest is to make sure none of the fuel lines are too close to a heat source including the ones coming from the gas tank. Then you can wrap the lines under the hood with an insulation material. Also for help at the Drags where most of my vapor locks occured, I used a "Cool Can", you know the device that looks like a coffie can with a coil of fuel line running inside it and you put ice or if you can find it, dry ice in it.

allcarfan · Jun 8, 2005

Spanish Dave said:
The engine cut out on tickover then starter moter just clicked but didn't turn the engine ... (this was sorted by tapping the solenoid on the Summit mini starter) but the car would not fire up.

Are you sure you dont have a loose wire in your electrical system? Thats the #1 indicator that your battery may be going dead or your alternator/generator is not charging efficiently.

Spanish Dave · Jun 8, 2005

65ShelbyClone said:
Back in highschool I had a '65 notchback with an overheating problem and even here in CA's 100+ heat, it never vapor locked on me. It did the same thing you described, though, with the filter filling back up after cooling off. All my friends' cars did it too, but never vapor locked. Something to consider is an electric fan for when you're moving slowly. You might also look into a phenolic carb spacer to keep manifold heat from transferring to the carb itself. Also make sure your fuel line isnt near a heat source like headers.

I have an electric fan fitted with an aluminum rad ... the car runs toward the bottom of the temp gauge on normal highway driving ... I also have a half inch Edelbrock wood carb spacer. It has been hot here this last few weeks (86 - 87 degrees) I am wondering if I need a second, or a bigger fan, and if I should put another one as a pusher ?
The fuel line is stock to just before the stock mech fuel pump where I have fitted the fuel filter. After the pump it is braided aero hose which was running next to and touching the cylinder head, but I re-routed that in case that was the problem ... no better.

Spanish Dave · Jun 8, 2005

allcarfan said:
Are you sure you dont have a loose wire in your electrical system? Thats the #1 indicator that your battery may be going dead or your alternator/generator is not charging efficiently.

I have checked the electrical system and contacts out ... all seem OK. It never gives any problems when cold. The alternator is a fairly new 100 amp one wire setup .... I'm sure that the heat is the thing.
When we were racing there my buddies 78 Corvette had a similar problem with it's starter which he never had before and he reckoned that was due to the heat.

orffiveo · Jun 9, 2005

Time to throw an EFI motor in there.
Just kidding. That would solve it though.
Seems like you're on the right track. Haven't had an old Mustang in a while, so I can't remember the in's and out's of them, but on my old carb 302 Bronco, a small low pressure electric pusher fuel pump inline helped my hot fuel problem. You could run in all the time or put it on a toggle too as it might your mechanical fuel pump acting as a heat sink when it gets hot.
The other place is usually where the others have said in the line or between carb and intake. At least usually. Good luck.

10secgoal · Jun 9, 2005

I had a similar problem. My fuel inline would get very hot and the gas in it too. It tried to start a burnout and the car backfired and died. Gas takes forever and a day to burn. SO I took some of that aluminum looking heat sheild and slid it over the line. Now when I do a jet change, I feel the gas, and it feels, slightly warm, if that even.

rbohm · Jun 10, 2005

to cure vapor lock i recomend using an electric pump near the tank to push fuel into the stock mechanical pump. for building a starter heat shield, just grab some sheet metal and cut and bend untill you have a heat shield that gives you about 1" clearance between the stater and the shield, and at least 1/2" clearance between the shield and the exhaust. you can also wrap the exhaust header with high temp wrap to retain the heat in the exhaust.

How Do I Cure Vapor Lock ??

Spanish Dave

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Spanish Dave

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Spanish Dave

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orffiveo

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10secgoal

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