1984 Nissan Sentra Engine stalling

The engines stalls at my 1984 Nissan, 73000km, automatic, after warming up. Everything is fine after a cold start until I stop it for a few minutes, then it will start but stall right away. Sometimes I manage to get it run in neutral transmission position, but even then, it eventually loses power until stop. I do not feel any response to more/less gas. The car has not been driven since 1997, and since 1991 only 3000km. So I changed oil+oil filter, changed the alternator belt, topped up all liquids. Amazingly, it did start right away and after some initial adjustments (brakes/timing.), It even runs up to 100km/h. Not more though, even if I give the engine more gas. It seems that the engine kind of coughs a bit. Only at 90/100km/h though. Did clean the plugs.

My guess would be that I should change the fuel filter (acceleration problem at 90km/h?) And I heard about an overheating problem of the distributor cap (would explain the warm start stalling). Apparently it could be replaced by a cap of the 300ZX with rotor (is this also a 4cyl? ). How is this done? Any advice would greatly be appreciated.
Thanks