Why is my car putting and wanting to stall?

I have a 1992 Oldsmobile Trofeo that acts as though its going to stall. Some work has been done on it and this little quirk is something the car just recently started doing. Whether the car is on idle or being driven it sort of putters and jerks a little and seems like its going to stall. Sometimes when it does this the car needs shut off then restarted and it will be fine but only for a short time and it will begin again. I've tried fuel injection already. Could i need a new fuel filter possibly? Oil change just recently done and all hoses seem ok. Anyone got any clue?