Low Idle and Stall when Warm
 

Recently, my 82 911SC has experienced a odd issue. The car can be standing unused for weeks, and it starts up right away. Never has a problem on cold starts, except for some white smoke occasionally. The problem is that after driving the car, and then shutting off the engine, on restarts (after sitting for a little while), i have trouble keeping it running, the idle drops and unless I keep giving it gas, it just dies. However, once I start driving again, after a minute or two, it runs fine. Any thoughts? Thanks

A bad fuel accumulator causes poor hot start characteristics.

Thanks - is that a major repair?

Without knowing more about the general condition or maintenance of the engine, it's all just guessing.
Hot start issues:
Check valve on the fuel pump.
Accumulator.
Fuel filter.
Vacuum leak.

And a few dozen more......................

It could be a gummed up fuel distributor due to "old fuel" in the system - lack of use.
I would replace the gas in the tank with fresh 93+ oct, add concentrated Techron and take the car for a long/spirited drive with lots of WOT. That might flush the "bad stuff".

Gunter is correct in that there are other things to check but, judging from your description of the starting/running behavior for a hot motor I would bet on the accumulator. A gummed up fuel system, clogged filter(s) vacuum leaks, etc. would have a tendancy to affect the performance either when the car is cold or hot.

A fuel accumulator is not a major repair. A few wrenches, some busted knuckles and your done. It is the olive drab cannister thing on the back left side of the engine compartment.

Thanks so much for the responses, at least I now have a starting point. I'll check out the accumulator.