Mitsubishi Repair: whats wrong wit it, catalic converter, head ache

Question
k i drive a eclipse 93 1.8 Sohc i just bearly bought the car and its giving me a huge head ache thats what happen i drive the car for like 40-50 miles then the RPM drop to zero and comes back and it looks like that the car don't have gas but it does. SOmetimes it dies so i just start wit the clutch sometimes it goes and i usually stop for 10 minutes it runs for 10 minutes until it starts doing it again i go to work on the morning it runs just fine but if i need to go somewhere else after that i have to leave it sitting for an hour or so so it will start and i took it to the mechanic and he check the presure on the fuel Pump he checked on the fuel filter ( i'll replace that one anyways)
so he said taht it could be the catalic converter thats old and its blocked so if you understood my question please help me!!!

Answer
Stefano,
Have your mechanic also check to be sure you're getting proper spark.  You may have worn spark plugs and a worn distributor cap.  You should also have your mechanic inspect the car's computer.  Older Eclipses are known to develope computer problems as they get older, and if the computer is damaged, it can cause these sporadic problems like the ones you're seeing.
Good luck!