I am getting deeper
 

My 1990 911 keeps going dead as I pull up to a stop sign, red light, etc. I have a guy that will work on it without losing a couple of rooms of my house and a small child. Although he is an excellent mechanic, he is not that familiar with Porsche engines. He needs to know what to change out. Here are the following guesses:

1. DME relay
2. Possible vacuum leak
3. Ignition coil and wires
4. Torque the manifold bolts down. Check the torque setting. I know on the carrera's it at 18 ft/Lbs
5. I was told there are 2-3 switches/relays that could be the problem, but I am not sure what they are called (any idea).
6. Head Temperature Sensor (located on cylinder head 3)

I know it is hard to diagnosis someone's problem without seeing the car, but I sure appreciate you trying. Thanks.

Check here ...

http://forums.pelicanparts.com/showthread.php?s=&threadid=245453&highlight=excell ent+mechanic

or here..

http://forums.pelicanparts.com/showthread.php?s=&threadid=245393&highlight=excell ent+mechanic

But the real question is why would you let someone work on your car who is not knowledgeable with Porsche???

I saw the links, but everyone seems to have a different opinion?? To get a clutch, alternator and address the idle problem it will cost me over $3k at a certified dealer (I have priced it). If I can help in identifying the problem and tell the mechanic what to do, it will probably run around $1,200.00. I can take the money saved and put it aside for the next problem. I will either be very smart or stupid. Besides, if the mechanice doesn't do well - big deal. I will take the loss and learn from my lesson. I am just trying to avoid as much sting as possible and enjoy the car.

Check the idle contol valve.

x2 on the idle control valve, cleaning it out might be all you need.

You really should have a spare DME relay on hand, cheap insurance.