Z20NET not starting in cold weather !!HELP!!

[axelparviainen]

So my 2004 Vectra C 2.0t suddenly didn't start in the cold weather yesterday (-15 celcius today). I've tried to jumpstart the car but it still wont start even though it cranks good. It did start by pushing it although that was quite a lot of effort before it finally started. When I got it running it was running smooth without any problems. When it was warm it started well but after a night of sitting in the freezing weather it won't start again. Today I put some starter fluid through the throttle body but it wouldn't start, I guess it would have started by pushing it but that won't fix the issue.
Have you got similar problems and what could this issue be?

To clarify:
-Cranks good
-Fuel pump is working
-Fuel filter recently changed
-Starts by pushing
-Runs smooth when warm

Any suggestions/help would be greatly appreciated.

[northpole]

if the car refuses to start when cold there will be an error logged in the ECU so i would scan it but it could be something as simple as a duff crankshaft position - or camshaft sensor that is causing it not to start... now don't go and change them without scanning the car.... as it could as well be a fuse that has blown... so scan the ecu.

[axelparviainen]

I forgot to mention but I also scanned the car for fault codes but nothing showed up.
This morning I tried starting it again and it started for about 2 seconds (very roughly) and after that it shut off and didn't start again.

[soulman]

could be faulty plugs /coil pack or Maf ?

[axelparviainen]

I changed the spark plugs a few weeks ago so maybe not that then? Can it be coil pack or MAF even though it runs and starts good when it is running?

[troutybrown]

Check coolant temp sensor reading

[axelparviainen]

Coolant temperature reading was -12 celsius, same as air intake temperature.