Sounds like a combination of things! As far as when you are trying to get the car started and you get the "scratching" noise, that'll be your starter, being an intermittent problem and all, it is a "dead spot" You want to get that rebuilt or find a replacement..
The OTHER problem, where do we start? Is an 84 so that must have the CIS-E injection or L-Jetronic right? Could be fuel pump, faulty cold start valve, shit, you may just need a complete tune up!! When it is running does it run well and have all of it's power? ( well, as much as you get from 318) On the other hand it could be a faulty ignition component, givfef us more on how it is when running..
I believe that car has a timing chain as well, FYI