MY 1966 C2 CORVETTE 327/300HP BOGS DOWN AT 4000 RPM WHEN IT IS PARKED IN THE SUN FOR A FEW HOURS. IT RAN GOOD IN THE AM. PARKED IT AT A CAR SHOW WITH THE HOOD OPEN AND WHEN I LEFT IT WOULDNT RUN PAST 4000 RPM.
18 Answers
Is this a one time occurrence? Did the problem clear up after a few miles?
IT HAPPENED A FEW WEEKS AGO. IT WAS AT A CAR SHOW WITH HOOD OPEN AND SUN BEATING DOWN ON MOTOR.
Possible fuel system partial vapor lock?
Vapor lock is caused by fuel vaporizing between the fuel tank and carb. The fuel needs to be liquid when it enters the carb. The engine being in the sun may have got the fuel line from the fuel pump to the carb hot and vaporized the fuel in the fuel line. It will go away on it's own when things cool down. It is possible that you have another issue. How old is the fuel that is in the tank?
Car was just restored. 200 miles on it. New lines. Fresh fuel....used another source.
If the weather was cool and the sun on the engine hot, the choke may have been open more than it should be for the ambient temperature but the problem would stop once the car was warmed up.
The classic solution for vapor lock is to insulate fuel lines and route them away from heat sources. If you would answer my questions I can better help you. Lose the ALL CAPS PLEASE.
THAT SHOULD NOT HAPPEN. IS IT THE STOCK POINTS DISTRIBUTOR? CHECK POINTS, DWELL, BAD CONDENSOR, MISFIRING IN THE CAP. COULD ALSO BE CARB DRIPPING INTO INTAKE AFTER SHUT OFF. COMPLETE TUNE UP IS IN ORDER.
Yes. All stock. Checked points and dwell. All set perfect. New plugs. This happened once before when I was in a parade. Temp went to 230 degrees and started backfiring and missing. Next day it was perfect.
Welcome rot the world of old engines and carburetors. This was always a common issue when it got hot. The fuel will vaporize and not flow into the carb as liquid. The engine will seem to lock up, and that's why it's called vapor lock. If you have stock black rubber fuel lines, you may consider something that reflects heat like chrome mesh or aluminum lines that will not absorbs the heat as much. I have seen people close the hoods of the cars one to two hours before taking off to cool off the heat from the sun. Red necks just wrap the lines in aluminum foil. Looks like crap on a show car or a wash and sine show car, but it works.
If the car is overheating in parades you should install a high capacity radiator and maybe an electric fan.
F-O-R I believe the issue was vapes locking. He also appears he wants to keep it looking as stock as possible. The old /corvettes always had overheating issues though. Its the design of a very tight engine compartment and not enough engine ventilation. Yes a high capacity radiator and electric water pump may help keep the car run cool, but the car will still get vapor lock on hit days at low speed in town.
Vapor locking is caused by heat. Reduce the heat and you will reduce the problem. Insulating the lines as I previously pointed out will also help. My Jag does not like stop and go traffic either. The cooling system is good but the stock fan cannot move enough air. I do not think it has anything to do with vapor lock, just a lot of things not working properly when they are hotter than they are supposed to be.
You cannot have it all. Either upgrade the cooling or don't drive in parades!
Water Wetter by Redline reduces operating temperatures due to better heat transfer. It has worked for me. Not a cure all but it helps.
fixed it......kinked fuel line.
Thanks for letting us know what the problem was. Glad you got it fixed.
