[914obsession]

Is there any particular issue that would cause this, I'll work on getting the pressure tester but in the meantime is this a common CIS (with oxygen sensor) problem? Is it likely an issue with the warm-up regulator.

If the car starts up from cold it will run perfectly for hours, if I shut it off for a few minutes to an hour or two and restart it it will run poorly?

Can the warm-up regulator from an earlier (1978) CIS system be swapped out for the one on my car (a 1980 unit)?