Nissan Primera 1996 1.87ltr will crank but not start when cold but starts when warm

If it won't start, how do you get it warm?

The mixture is generally controlled by the coolant temperature sensor. Usually a thermistor which can be checked by measuring the resistance hot and cold. Which would normally range from a couple of hundred ohms to a few thousand. And check the wiring to it for damage too.

No idea what sort is used on your car, though.

Pretty much impossible to diagnose with such scant information.

Are any warning lights coming on?

What age/condition are the plugs?

Can you hear the fuel pump priming?

Did it just begin, or has it gradually got worse?

Does it run perfectly as soon as it starts?

Chris

Has it got a carb' or injectors?

Injectors.

Practically nothing sold after 1992 would have a carburettor due to their inability to meter fuel accurately enough to meet emissions legislation.

Chris

Thermostatic throttle opener. Check the long line on the opener cam lines up with the pin on the lever when cold.

Idle air valve, should be open. If fully opening the throttle improve starting this is suspect.

Injectors check they tick when engine/CAS turned over.

Temp sensor.

Check plugs.