My girlfriend has a 2003 f150 4.6lt pick up its a great truck most of the time. Problem is when the temp gets in the neg double digits it becomes very hard to start it cranks fine but doesnt want to fire. When it does fire it might stall afew times before it stays running. The last cold snap we had I replaced the battery and in the summer the starter got changed. I have heard that this model of truck are known for hard cold starts. I am just wondering if this is true and if theres any thing to help it besides block heater. It is strange that my 89 gm pickup will start no matter what temp and I'm having problems with the newer truck.

 

No it's not true they have any reputation for hard starting.
The systems are all the same from 97 to 03.
My 02 starts perfect in below 0 temps.
There is an issue with the IAC, the IAT, or the CHT sensors..
These are key parts of the cold or hot starting sequence.
The computer looks at the values of these sensors to know it is to be a cold start and set fuel, timing, and IAC opening to proper levels.
First clean up the IAC and throttle body.
Test fuel pressure, then if still a hard start, a Scanner needs to be used to look at the IAT and CHT for being out of tolerance or their resistance values need to be checked with a meter for proper reading at the temp they tested at. Hard to test in cold temps on the truck outside.
Good luck.