I've never seen one of these in person. If it is the type that has weights on the spokes that slide toward the rim with "centrifugal force" then I suppose you could check to see if the weights are able to slide freely on the spokes. I would think that if the weights are stuck from dirt and gunk on the spokes the bike won't function properly. Just a guess. Maybe someone else will have a better idea.
Sounds like you need to get ahold of autobike (the manufacturer) and order a new crankset. they are ok to work with and will sell you the cranks. the autoshift bikes are department store quality bikes with the autoshift rear der which somehow constitutes a 2-300 dollar price markup of those bikes when new. Same with the landriders.
Had one once... If i remember there is a 'ratchet' mechinism in the BB like on a derailer which may not be working correctly. You may have to take that apart to see if the pawls of the ratchet are stuck and therefore not engaging ... ... ..... peace