850 won't start under 0 celcius unless using block heater

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1995 volvo 850, non-turbo 20 valve, 220000 km.
Here's my problem: The car has new sparkplugs, wiring, rotor and cap distributer, new rpm sensor, new temperature sensor and new fuel filter. There are NO error codes stored in the ECU...The car start with no problem when it's warm and runs OK and has never stalled while driving. It will not start when it is below 0 celcius unless I connect the bloc heater for an hour or 2 depending on how cold it is outside. Also the battery is good and I use mobil one oil. I use to be using 8.3l per 100km and now I'm using around 10.5-11 per 100km...

Any help would be very much appreciated

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