94 Accord, problem with idle

[lightning21]

I have a 1994 accord with the F22B2/non v-tec. I replaced the engine last winter with a used engine from japan with ~50,000 miles. The injectors on the jap engine were bad so I just pulled the ones off the stock engine. It has a CAI and straight pipe exhaust on it. I have not been able to get the idle adjusted on the new engine. The engine idle screw seems to have little to no effect. I replaced the cap and rotor, plugs, wires, egr valve, map sensor. I finally resorted to forcibly adjusting the idle by tightening up the throttle cable so it idles at about 1800 rpm with the throttle open a little. It will stall sometimes when I stop, it seems to happen more when I stop abruptly. I was thinking perhaps it could be the ignition coil? but I don't know for sure. Any suggestions? Thanks.