i need some help!!

ok my brother n law bought this 1990 eclipse gs turbo 5spd. ok he bought it and the guy told him the ecu was bad ....so he goes out and buys a used ecu..it gets installed and we get fire on 1 and 4 cyl. the car starts and idels fine but goes to give it gas and it bogs out and smoke comes out the exhaust..not sure what color but seems to me it was gas..ok so we go to the part store assuming it was the coil and we replace the coil..we install it and it only fires on 2 and 3 cyl...so we pull all wires 1 at a time and check for spark..now we are getting nothing on any of the wires....does anyone have any idea what is going on with this car...i have a 2nd gen but never come across this with mine so im clueless...ive read several threads saying cas sensor could be bad..if so how do i check it....or could be the ignition control module..the thingy that sends the coil its signal...i dunno what it could be please help

thanks mike

ive never had the cas sensor go but that seems to be the only likely cause. I dont remember exactly, but I think there is a check engine code for the cas. I never did like where they put those coils on the 4g63 engine though. If you have the haynes manual for the car, it should tell you how to check for resistance in the circuit to test the sensors.