I have a 98 Mazda 626 lx 2.0 L 4 manual 5 speed tranny started hiccuping about two weeks ago. At first it was mild than it got worse and almost constant . I pulled the thermostat and it appeared to be stuck shut. Car than ran fairly good for a few days with very minor hiccups but didn't last long. Car started hiccuping really bad yesterday , tach gauge goes crazy when it has these hiccups, than car stalled while driving and wouldn't restart this time. Does anyone has any answers of where to start first? Didn't have these issues until I replaced the clutch a lil over a month ago.