rough idle

1993 xr7 cougar, Has a rough idle, I've replaced plugs, cap, rotor, wires, coil and fuel filter. No trouble codes and no signs of vacum leaks. Sometimes when I first start it, runs smooth until a tap the gas and the rpms drop and rough idle, when driving it feels like its missing and low on power. Any ideas?

Thanks
Scott

1993 xr7 cougar, Has a rough idle, I've replaced plugs, cap, rotor, wires, coil and fuel filter. No trouble codes and no signs of vacum leaks. Sometimes when I first start it, runs smooth until a tap the gas and the rpms drop and rough idle, when driving it feels like its missing and low on power. Any ideas?

Thanks
Scott

mine does the same thing replaced everything like u also intake gaskets & checked timing My intake was full of carbon deposits , im thinking maybe the exhaust is restricted (convertor) checkn tomorrow let ya know if it works. let me know anything as well