have a question on what i should do next.

I have a 97 f150 4x4 that had a misfire cylinder #2 did everything from replace plugs and wires to injectors. now the truck starts up but won't continue to idle unless given a little throttle, then itll idle but really rough. also blowing white smoke like a chimney. any recommendations to fix this

thank you

 

just went and looked at the fuel filter and noticed that the exhaust pipe close to the filter is leaking fuel... would that be caused by the injector being open and leaking fuel??

 

If you changed the fuel filter, there are little "O" rings that are located inside the female fuel line connectors that go on to the filter.

One of them maybe came out and wasn't noticed . They are special O rings that are resistant to gasoline , regular O rings will not work there.
They are only about 3/8 in in diameter, with about a 1/4 in center hole and are usually tan in color. Last time I needed one , only dealer had them.
If you check maybe the connectors were not on all the way. Keep in mind that line is under at least 40 lbs pressure or more.