I just drove 50 miles from a car cruise with my 78 c10 L250, parked, and turned ignition off. No problem. Ran beautifully coming home. 68,000 original miles on engine. After about ten minutes, I turned the ignition key and the engine wildly revved to no man's land. I shut off key. This is a 4 speed manual transmission. I have a weber carb and red line fuel regulator. I checked the throttle cable for movement. It moves. I was going to replace the cable because it was too tight from firewall to the carb. Have put maybe 1500 miles on cable. Is it the cable or vacuum or what? Please help!
It could be that the carb is stuck on the high step of the choke cam without the choke plate being closed. Maybe it's gunked up and just needs a little carb cleaner. There should be a little slack in the throttle cable. This definitely sounds like a carburetor problem.
