awhile back ,changed fuel pump /filter assembly as car was bucking at speeds over 50 mph and some hills when throttle was pressed down.VSA light,engine light etc all come on, but go away when it is shut down and then restarted. never got worse .stopped after pump assem. was done ,but came back after a short time. it bucks sharply but resumes if you let off the throttle and stay eased up . did it at starting yesterday (start ,stall out ,repeated 5 times then shut it off ,waited a couple minutes. started up and was fine . no paticular pattern except it will run normal ,then do it without any signs. another thing that is odd-- it occaisionally will lose all gauge functions ( fuel , speedo, tach., for awhile and then they will come back ?

 

Sounds like an electrical issue. Maybe a ground.