Originally posted by TheVaultDweller
Well, even his suitcase armour, which is one of his weakest and most basic armours, is strong enough to kick a car with enough force to send it skidding several yards. So I would say he still has a significant strength edge. But Cap has more than enough strength, in combination with his vibranium shield, to do some damage to Tony IMO, especially if he targets the weaker areas, like the joints of the armour.
Even with Cap's AoU feats the IM suit is still many times more powerful, in IM1 Tony caught an Audi SUV and held it for a bit while at around 10% power. Then he grappled and held Thor for a few moments in Avengers.
I don't think they're amping Cap in this film to be able to stalemate the IM suit, why we see Cap and Bucky having to tag-team Tony and we're not sure of the context behind that scene. Tony could have been hurt, drunk, having another emotional moment etc.