Seems tyo misfire in higher gears when approaching 50 mph with erratic idling.
1997 suzuki sidekick 1.8 litre, where are sparkplugs? Misfires when warmed up??? on 1992 Suzuki Sidekick
seek mechanical assistance. if you wish to tackle tune up on your own, service tech. usually more than happy to give council and recommendations. information is free.