Hesitation and Stalling (Cold Engine)
 

My '84 911 Cabrio (about 125,000 miles) starts fine and correctly idles when cold. However, once I get on the road, it hesitates and stalls when accelerating. It can be re-started after the stall, generally fairly easily. But the problem then repeats itself. After 4-5 starts and stops, the engine warms up and the car drives perfectly. Just changed the fuel filter, which did not solve the problem. My next thought is the cylinder head temp sensor, but would like to hear what others think. Thanks all!

You can check the sensor resistance at various temperatures.
I’m sure others will suggest many possibilities and they will all be guesses.
Best approach is methodical troubleshooting

if your head temp sensor is the original one wire type (they now have a two filament wire), you might want to proactively swap it out regardless

It’s original, and so given relatively modest cost I’m going to replace it as proactive matter. If problem solved, great. If not, it’s methodical troubleshooting time. Thanks.