Today I changed the connection for my vacume modulator to the same place as the FPR. While all this did was cause my car to knock like none other. But when I went to put it back on its origional fitting I found that it worked much better then ever before. I've read numerious post on 83s with chrysler ignition having hesitation problems. I also have such problems with My 83 thats why I switched the hose connections. The idea was maybe I was getting too weak of a vacume. But insted I got way too much. But since the vacume is operated at a very low pressure, I think it might be possible that they might begin to get stuck in and prevent you from getting a good advance. And maybe the stronger vacume freed up the plunger in the module. Just a theory. Any one else with these problems or any ideas help me out.