i believe there is a switch on the clutch pedal to stop over revving between gear changes, check the connections & adjustment, sit in the van with engine running & try to rev it up, if it won't rev, then pull the clutch pedal all the way to the top with your left foot & see if the revs increase. if that works then it needs adjusting. some drivers also ride the clutch with their left foot, which can cause the problem..
sid
January 2010