Warm start problem
 

My '84's engine dies after idling for about 5 minutes, then it won't start until it cools off. I know this is very common as I've seen previous threads for this warm start issue, except this topic always makes reference to 911 SC models. As far as I know '84 Carrera models are equipped with electronic ignition and I don't know if the type of test to be performed would be the same.
Thanks for your help

i would start with the CHT sensor

Others may chime in, but I think you could have a vacuum leak assuming your hoses are original. During warm-up, the fuel-air combo is a bit richer. Once warmed up, this combination is leaned out. If you have an air leak, your fuel is already lean, so you wind up stalling when the car reaches temperature b/c you got too lean.

What is your RPM during warm-up? I think it should be around 1200.
Do you have a Bentley workshop manual? You can test the CHT resistance.
Check to see that the intake nuts are tight, and that none of the vacuum lines have any cracks in them.
You could adjust the idle a tad, but do this only to help diagnose the problem.
If the car is idling when warm, RPM should be 800.
If you get here, then another test includes removing the oil cap (big air leak) which results in an RPM drop.
No RPM drop = air leak.

Let us know what's up - and welcome to the site.

+1, we need more data to help.

What is the RPMS at initial cold start and after 45 seconds what does it drop to and what is it at stall.

You wrote after cool it starts. +1 check the resistance (OHMS) of the CHTS, the white plug at the 3 plug harness behind the large plastic heater blower tube ( yes, you must remove the tube to gain clear access and also remove the retainer clip for the harness or you will damage the plug if you try to pry it off )

If you suspect a vacuum leak, use the old cigar in a vacuum line to locate a possible leak. Best place is the T fitting that goes up to the cruise control module. Get a 24-30 inch #2 hose from a FLAPS and light up a cigar and blow into it.

Oh yeah, for extra measure, check the voltage before and after stall.