Ron,

I don't think you can repair it as it is essentially a D-Jetronic injector. Well maybe YOU can, but it's not a basic DIY job

If you say the car stalls until warm, I don't think it's the cold start valve. The cold start only adds fuel for a moment, from what I've read. I'd check the temp sensors as well.

Sixto
91 300SE
81 300SD