To all of you that tried to help me figure out why my 1980 L82 was hard to start after driving it and letting it sit for over 15 minutes before trying to start it again, I have finally solved the problem. I asked for help from all of you a few months back and mentioned that the previous owner had welded the heat risor valve in the closed position. All of my friends and mechanics told me that it was impossible that the valve was still inside. Most everyone had the same opinon, your car shouldn't be running well at all if it was! All I knew was that I had a new Edlebrock Thunder Series carb put on and it made the car run fantastic. It fixed every problem but 1, and that was re-starting the car when it was hot and had sat for 15 minutes or longer. Long story short I told my mechanic that I wanted him to drop the exhaust from the heat risor and tell me for sure. Low and behold, it was in there and it was in the complete closed position. Prevoius to this I have had a thicker carb heat gasket added, fuel pressure regulator, insulated the gas line, checked and blew out the gas return line, checked the fuel pump out and even had the carb removed and tested for leaks. This is a glorious day for me! Mission accomplished, finally! Just wanted everyone to know that it is possible!

 

 

Mine broke and started rattling around. Wife said "what's that rattle?' Been thru 2 of them. May disembowl the next one.

 

1980 Heat riser valve is default spring loaded in the open position and closes on application of vacuum. All you have to do is disconnect the vacuum source and it should stay wide open.

Bubba tried, Bubba tried.

-Mark.