1980sc cold start problems
 

I have a cold start problem on my 1980 911sc. The car will start when I lift the air sensor plate for a second or two and then will start fine when warm. I have replaced fuel pump check valve and accumulator with no luck. Any suggestions would be greatly appreciated.

Since you've replaced the check valve and accumulator, the next likely suspect for loss of residual pressure (which appears to be your problem) is the pressure relief valve inside the fuel distributor.

Cold start? Do you have power to the CSV from the thermotime switch on the chain cover when cranking?

The thermotime switch provides the ground for the cold start valve. Make sure one of the terminals is grounded or you might have a bad switch.