[Lar911sc]

Hello! I have a cold start issue that I’d love some help diagnosing.

The car:

• 1979 911 SC
• 3.0
• 72,000 Miles
• Brand new tune up – wires, plugs, rotor, distro
• Clean fresh gas

When I start the car with a cold engine it fires right up, but immediately drops RPMs and behaves as if it will stall – but so far it hasn’t stalled out. After a few seconds the RPMs rise to ~900rpm, then up to ~2000rpm a few seconds later. The car stays at this RPM range for about minute before it drops to ~1000rpm and is ready to go. Once the car is warm this problem does not occur on restart.

Video of a cold start: https://youtu.be/t4ccCql7o-8

I suspect the WUR but was hoping that maybe someone here had experienced and diagnosed a similar problem before I throw a $400 part at it.

Thanks!