Your problem is the door check straps.
On these parts there are early units and late units. The early units are MUCH better built units. If you want to do a good job with the repair, order the early units. It takes probably fifteen minutes per door to replace them. You will need to remove the door panel to replace them. You must be careful so as not to ruin the door panel. If you have not done this before, let us know and we'll tell you how to go about it.