I've got a '94 626 2.0l 4cyl, 5 speed with about 80k kms (about 50k miles) that since it got cold has been acting odd. Up until the cold hit it was running great and this is the first winter I've owned the car.

It won't start unless plugged in if it's below -15C ( about 0 F) and 95% of the time when it is running it surges from 700-2000 rpm and back again constantly,it'll do it until I rev the engine up past the 2000 then it has no problem. It'll do it with the engine warm or cold.

I've noticed also that when I pull up to a light the heat coming from the vents goes down to almost half, that happens extremely quickly (a couple seconds).

Any help appreciated.