I have owned my 97 F-150 for about a year now and lately it has started to shake, sort of side to side when i start it, and then it starts and idles nicely. Anyone have any clue?

DT

Maybe you need motor mounts? Only other thing I can think of is maybe the fuel injectors are dirty and they're not all squirting fuel when it's starting.

First thing I would do is pull the plugs and check thier condition.make sure they are clean and gapped correctly. Also, look for fouling. Especially moisture (coolant or oil)