I have a 2003 Ford F150. When the outside air temp falls below -4, the truck will not start. It will turn over fine. It just does not fire up. I keep a full tank of gas in it during the cold months here in Wisconsin. It is the only time that the truck gives me any problems. Could it be the fuel pump or a sensor? Any ideas?
I had this problem with a V8 Ford. It turned out to be condensation in the fuel turning to ice chrystals. Solution was adding 2 small bottles of gasline alcohol to each tank full. You might try this as an inexpensive start.
Some Fords used to need an engine heater to start in the cold. The owner’s manual even used to recommend one. At least they are cheap.
If Iived in Wisconsin I would certainly have a block heater installed. They solve a lot of problems; easy start, long battery life, long engine life, better fuel economy, less complaints from wife how cold the car is.
I think you have a temp sensor problem, or perhaps some other sensor.
If there were ice in the fuel line, the starting problem would not go away until the ambient temperature was above 32F. Been there, done that.
An engine heater might help, but there’s no good reason your truck shouldn’t start at -4F, or lower. I’ve never had a vehicle that wouldn’t start at below-zero temperatures.
Start testing sensors. A service manual would be very helpful, unless you are willing to pay a mechanic to do the testing.