1979 911 SC Cold start issue

[Lar911sc]

Hello! First time posting and fairly new to the air-cooled Porsche game. I am experiencing a cold start issue described below.

The problem child:

• 1979 911 SC
• 72,000 miles
• 3.0

I am experiencing the issue when I start the car with a cold engine – it turns over easily and fires up quickly. A soon as it fires it drops RPMs and seems to want to stall –*kicks, sputters, but doesn't die. After few seconds it jumps up to ~900 rpm, sits there for a few seconds, then kicks up to ~2000 rpm where it stays for a minute then drops to ~1000 rpm once it warms up. As soon as the car is warmed I can shut it off and start it up with no issue. It has new non-ethanol gas in the tank.

I suspect the WUR, but before I throw a $400 part at it I wanted to post here in the hopes that someone has some experience/advice.

Video of car starting: https://youtu.be/t4ccCql7o-8

Thanks!