What year dod Porsche start using a DME?
 

Before this it was relay's and fuses that ran all of the systems correct?

Since the 1984 Carrera was the first electronic fuel injection 911 model, I'd say 1984.

84

yep, 3.2 in '84

As the OP didn't stipulate "911", I'm gonna point out that the Series 1 944, introduced in 1982, had a DME and the 928 apparently went Motronic half-way through Series 1 (1978-1982) for the 1980 MY.

Older cars used hydraulic fuel injection (Bosch CIS) and capacitive discharge (CD) ignition, unless they are old enough to use carbs and coil ignition (early 70's).

The '84 is a truly special car :).