I have a 1994 f-150 6-cylinder that shakes and rattles while idling and seems to run very sluggish when taking off. i,ve changed the fuel filter snd put in injector cleaner and still having problems. any suggestions.

I would start with a complete ignition tune up, ie spark plugs, spark plug wires, distributor cap and rotor.

It could be the IAC motor too and a very common problem with Ford products.do this first,unbolt it with it plugged in have someone turn the key on and off.It should move when the key is on and should go back in with the key off.If it does not move,try cleaning it out first with carb cleaner and try it first.If this does not work,replace it and most parts stores have them in stock.