Replaced the fuel filter hoping it would help, however the 91accord will idle fine. Once running for approx 5 minutes at idle, if you attempt to drive it, or rev the car up to 2500 rpms or more, it will choke itself down slowly, then backfire, almost completely stalling. The backfire is not to violent, but car is not drive able. It will return to idle, and never falter, stall or backfire. Any suggestions would be much appreciated.