1984 944 No start in the cool mornings

[MrWrong]

Now that the weather is changing I'm having problems starting my 944 in the mornings without a dose of starting fluid.

It's been in the 90's during the day and 50's at night here.

I'd say it's a fuel problem, but if sleep in (noonish, or like this weekend where I had it on jack stands all weekend) it'll fire right up fine on the first crank without the spray bottle. So I don't believe its a check valve or a damper or regulator or leaky injector draining the system.

I don't think its a spark issue since it fires up either way.

For these reasons I'm pretty sure its temperature related.

Any clues where to look??

[Gordon Rankin]

Get a multimeter and test the voltage in your battery after you've left the car overnight. If its 12.5 or less, you may have a short thats draining the battery at night or you may have need of a new battery.
I had the same problem last year and discovered a short in my dome light that would drain the battery at night. In the colder morning I could not get the car to start but if I waited till later in the day, the car would start.
I am not familiar with the physics involved but I know this worked for me.

[MrWrong]

Sorry, forgot to mention that I don't have a problem cranking my life away.

I just put a new battery on it back in June when I got serieous about getting this beast running. It had been sitting in a barn for 4 years after the PO broke a timing belt.

I'll get the multimeter out of my tool box when I go home this weekend.