Well I'm puzzled too.

The alternator is new and the battery is good - started the car in low temps several times on a trip last week across the Rockies from Calgary to BC. Turned over like a champ in -11C temperature after sitting in a lot in Calgary for a week.

All I can tell you is that if I let the glow cycle complete she turns over perfectly.

If I rush it when the engine is warm, it fails to turn over once every 10 or so starts - just get the solenoid click.