i have a DOHC zc in my 91 hatch. woth a pm7 ecu. i was wondering what people are gettin for mileage with zc's? i am gfetting 26 mpg. it seems pretty low to me. i know that these ecu's are not the best for fuel economy. what can i do to increase my mileage? i have new o2 sensor, plugs,wires,cap,rotor. i am also getting some black smoke which means im burning a bit rich. any help would be great