83 944 cold start problem
 

This is my first post and my first Porsche. This car runs great on days that are 80 but if its 65 it don't get tack bounce or spark. If I heat it up with a heater it starts fine. were to start.SmileWavy

I'd start with buying new speed n reference sensors. Or, if you have an extra, replace the DME relay.

Coolbreezz, How well does the car run when it is warmed up? Does the idle drop when you stop and then back up? Does it sometimes act like it wants to dye out at idle? Mine did all this as well and it was my coolant sensor for the DME. Now it runs so good I am in heaven.

The DME temp Sensor is an easy and inexpensive replacement. I'd start there like Alan says.