1. change your fuel filter
2. check you distributor cap and rotor
3. with the car running in the dark open your hood and see if anything is badly arching, if it is you need to replace that spark plug wire and or spark plugs.
4. check your air filter
5. check all vacuum lines carefully or just listen for a vacuum leak.
6. replace your spark plugs they are relatively cheap, cheaper then a tank of gas.....