i have a 1969 912. You need to pump the gas pedal to get it to start. Really pump it very fast. Is there some thing I could clean out or change? Once it is running and still at least warm it starts right up with just a pump of the pedal just after you turn the key.
It sounds as though it isn’t getting the correct fuel/air mixture when cold.
The choke in the carburator may be sticking open.
There’s a problem with the cold start choke system.
If you know nothing about carburators, find someone who does. And then they need to know how to work on Porche carburators.
this sounds as if the automatic choke is failing/or has failed.
this should be checked into. an early auto choke is usually just replaced with a manual choke. these require a manual (operated by YOU) choke cable.
you could probably pay for a professional to configure a replacement for this. but would you, since you came to this forum?
It’s time for a carb rebuild. If it’s on it’s original, you are lucky it’s still running at all. Valve seats wear out, sediment builds up in the bowl, jets get gunked up.
And no, carburetor cleaner will not fix it.