My 98 Sportage started running very poorly recently, Only code was misfire # 1 cylinder. Changed plugs, wires and even coil and then swapped coils front to rear, still no spark to# 1, prior to this we did compression test all cyl's around 130psi all seem to be getting fuel and we removed front timing cover, all marks line up and key way on crank is tight. At this point I'm some what stumped, cyl's 2,3,4 all seem to be functioning normally. The same coil fires 1 and 4, why is 4 ok but cyl 1 dosen't fire? what triggers coil to fire and do they both 1 and4 fire at the same time?, possibly cam sensor, crank sensor, ECM?? Im not sure where to go at this point, wouldn't 2,3,4 firing normally rule out a bad sensor?