72 911T cold start/idle problem

My 72 911T (MFI) is hard to keep running on a cold start. Catches after 2-6 cranks but will not keep a good idle until it reaches 180degrees. Warm starts are no problem. I am missing a warm air mixing box (saw one in a picture and see the hole in the drivers side tin shroud where the hose would go) I can only assume that the lack of this part is only partially to blame there must be something else. any ideas. Relay?

Do you use the hand throttle? I realize it doesn't really answer your question, but may be how Porsche expected us with early cars to deal with the issue.

Yes I use the throttle, and I am sure thats one reason the engineers had it installed. Frankly, I think it would be a nice option in all cars. That and a hand brake! anyway. I know that there is something more to this cold idle problem. I'm just not getting it yet.

H ave you checked the warm up thermostat at the front of the MFI unit? It's the one with the black ribbed pipe running to it. Firstly make sure the pipe is not cracked or worn through along its entire length. There will be a hose clip at each end.
If that checks out, dismantle the thermostat mechanism. It gets blocked up with gunk/leaves/dirt and the expandant washers within can not function as they should. It's a nice piece of engineering and is designed with this servicing in mind. Don't take the washers off the shaft as they can get mixed up and alter the warm up characteristics of the engine. They should be in a ()()()()()() pattern.
That's the most obvious soloution to your problem.
The warm up device used on the air cleaner housing may help too, but I've never had one on mine. It seems most people take them off.

And yes, that's what the hand throttle was designed for. Use it- it's fun!

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'72 911 TE