1984 Carrera 911 Hard to Start

[PilotGabe]

1984 Carrera 911 3.2 I'm having problems starting. Once I start it with either it runs fine. I believe once it warms up it well start with no problems. Changed ECU, Relay next to ECU, Fuel Pump & Check Valve, and we have a very strong battery. I'm tired of just replacing good parts. Has this happen to you or does anyone have an ideas?

[jstobo]

Check your temperature sensor with an ohm meter. At lower temps it has high resistance to tell ECU to richen the mixture. Once warmed upped the resistance drops. A shop manual should show you resistance vs. temp. I have put them in a water bath on the stove to test. Put a thermometer in the water and read the resistance as you heat the water. Hope this helps.