1998 Mitsubishi Galant miss firing

Electrical problem
1998 Mitsubishi Galant 4 cyl Two Wheel Drive Manual 99. Ooo miles

yes, my car was runing good, and all just started to run like it was miss firing, but I replace spark plugs and wires and cap and router and still acting that way and sometime when it cold it almost seems to be gone, I pretty good with car but this has me baffled, please help me with this, also car it berning white all 4 cycl