My Punto has finally decided it doesn't like the cold weather.
It's refusing to start until the engine warms up - takes about 10 mins of turning the engine over (Public enemy No.1 in our street - I leave @ 6:20am). Thankfully battery is HD type so can take it.
Once started, after a few stalls and hiccups, it runs fine. Until of course I stop and the engine cools down.

Is it as simple as changing the engine coolant sensor, or is there another temp sensor for the injection system I don't know about?

I've also noticed that within the past week the temp gauge jumps around.

Oil and water levels are OK and no leaks anyware (Apart from the usual oil leaking from the filler cap - naff design)

I would check for a new thermostat....that worked on my Fiat Tipo. It´s only about 15£! And also check the battery water level. If the battery is old, than it could be an idea to buy a new one! You can also check if there is any link problem in the ignitioncables, if it is, spray some contactcleaner on them. It worked on my new Punto mk2. Italian cars just don´t like cold weather

sound like problems with ignition sytem to me plugs/leads. are you plugs old?? what about teh ht leads? this is the sort fo weatehr were problems will show up.

my sister had exact same problem replced batter fliter and plugs and the car is like new now well worth doing a service not even that much effort

Cheers for the replies.

Yes, it was the Coolant temp sensor.
The easy check, though it took me a while to realise, was to disconnect the sensor. The car started straight from cold + ignition warning light on dash came on. Once the engine had warmed up after 5mins, just popped the connector back in. Not perfect but it'll do the job until I get a new sensor from fiat.

Note - If you ever need to replace this sensor make a note of the colour of the connector head of the sensor (blue, black or red) and the number of pin connections (1, 2 & 3). They fitted different types to the same models.

Cheers
Neil