Q: Car won't start in cold weather, even after gas added.

This may be related to many different possibilities, some of which may be related to a lack of spark and some of which may be related to a fuel delivery problem or a combination of both. For example, if the ignition coils, crankshaft position sensor, spark plugs, spark plug wires or ignition module are faulty, this may cause the motor to not produce the spark needed to ignite the fuel in the motor. If there is a fuel delivery problem, this may be related to low fuel pressure, faulty or dirty fuel injectors, a faulty or dirty idle air control valve (this relays information about air intake to the computer which makes fuel adjustments), or potentially a faulty fuel pressure regulator or fuel pump. Fuel delivery problems will typically not allow the proper amount of fuel to be delivered to the cylinders which results in a lean fuel condition which can cause backfiring or simply cause the motor not to start as a result of fuel starvation. I would recommend having an expert from YourMechanic come to your location to diagnose your no start problem.