Tuning problem? timing? Vapor lock?
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Joined: Apr 2008
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Tuning problem? timing? Vapor lock?
Ok. Was working on my vapor lock problem with some wrapping of the fuel lines and took the car for a test drive to only now have a new problem. Engine is a 68 327 with an Edelbrock carb.
She started right up per usual. I took her about 3 miles and decided to turn around. When I got to the stop sign she stalled. Got her running again, but it took longer than usual but she stalled out again. Got out and increased the idle and started her again. There was some hesitation when I started out from the light but she ran ok, but whenever I hit the gas to accelerate she hesitated and then went.
Got her home she stalled again. Got it started but took three turns of the key and she ran rough then stalled again. Pulled the air cleaner and notice gas dripping on one side for about a minute after she shut down. Now she's acting like she's flooded....now will not start.
What is going on?
She started right up per usual. I took her about 3 miles and decided to turn around. When I got to the stop sign she stalled. Got her running again, but it took longer than usual but she stalled out again. Got out and increased the idle and started her again. There was some hesitation when I started out from the light but she ran ok, but whenever I hit the gas to accelerate she hesitated and then went.
Got her home she stalled again. Got it started but took three turns of the key and she ran rough then stalled again. Pulled the air cleaner and notice gas dripping on one side for about a minute after she shut down. Now she's acting like she's flooded....now will not start.
What is going on?
Thread Starter
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Racer
Joined: Nov 2004
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From: Oakville ON
A common misconception is too much fuel is vapour lock. Vapour lock is correctly defined as fuel NOT getting to the carb because fuel in the line before the pump is too hot and generating fuel vapour, which the pump cannot draw in. Pump can only pump liquid because of design.
Too much fuel is percolation - fuel after the pump is too hot and vaporizes which causes an overly rich condition - solution to that is insulating the line after the pump or a thermal spacer between the carb and intake manifold (depending on the actual cause). This usually happens after a hot shutdown and some time. Car may start if accel pedal is held to the floor while cranking, clearing the over-rich condition. I had a car years ago that was a bi*ch to start 10 minutes after a hot shudown. Installed a factory recommended thermal insuluator betweeen aluminum carb and aluminum intake and voila!, never had problem again.
Reference: Peterson's carb and fuel systems #6, c: 1977.
Too much fuel is percolation - fuel after the pump is too hot and vaporizes which causes an overly rich condition - solution to that is insulating the line after the pump or a thermal spacer between the carb and intake manifold (depending on the actual cause). This usually happens after a hot shutdown and some time. Car may start if accel pedal is held to the floor while cranking, clearing the over-rich condition. I had a car years ago that was a bi*ch to start 10 minutes after a hot shudown. Installed a factory recommended thermal insuluator betweeen aluminum carb and aluminum intake and voila!, never had problem again.
Reference: Peterson's carb and fuel systems #6, c: 1977.
Last edited by Rich's'78; Jul 13, 2011 at 08:01 PM.
Race Director
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A common misconception is too much fuel is vapour lock. Vapour lock is correctly defined as fuel NOT getting to the carb because fuel in the line before the pump is too hot and generating fuel vapour, which the pump cannot draw in. Pump can only pump liquid because of design.
Too much fuel is percolation - fuel after the pump is too hot and vaporizes which causes an overly rich condition
Too much fuel is percolation - fuel after the pump is too hot and vaporizes which causes an overly rich condition
Correct in all details, including spelling of vapour 
Race Director
Joined: Mar 2006
Posts: 14,112
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From: Florida
Ok. Was working on my vapor lock problem with some wrapping of the fuel lines and took the car for a test drive to only now have a new problem. Engine is a 68 327 with an Edelbrock carb.
She started right up per usual. I took her about 3 miles and decided to turn around. When I got to the stop sign she stalled. Got her running again, but it took longer than usual but she stalled out again. Got out and increased the idle and started her again. There was some hesitation when I started out from the light but she ran ok, but whenever I hit the gas to accelerate she hesitated and then went.
Got her home she stalled again. Got it started but took three turns of the key and she ran rough then stalled again. Pulled the air cleaner and notice gas dripping on one side for about a minute after she shut down. Now she's acting like she's flooded....now will not start.
What is going on?
She started right up per usual. I took her about 3 miles and decided to turn around. When I got to the stop sign she stalled. Got her running again, but it took longer than usual but she stalled out again. Got out and increased the idle and started her again. There was some hesitation when I started out from the light but she ran ok, but whenever I hit the gas to accelerate she hesitated and then went.
Got her home she stalled again. Got it started but took three turns of the key and she ran rough then stalled again. Pulled the air cleaner and notice gas dripping on one side for about a minute after she shut down. Now she's acting like she's flooded....now will not start.
What is going on?
Couple ways to fix it, with proper gaskets and heatshield, or block off the channel.
If a regular manifold, then just check you needle and seat for proper operation and possible vacuum leaks.
Le Mans Master
Joined: Mar 2008
Posts: 5,948
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From: Oxford MA-----You just lost the game!!!!
Ahhhh, the King's English...........but he mis-spelled aluminium, didn't he?
