if your ecu is "bad" it usually wont let the car start, if it does it will run like bootycakes. theres multiple reasons as to why you dont have power when you hit the gas. do you have and check engine lights at all ? if your ecu is bad you should have a permanent check engine light on. looking at your user name im going to assume you have a 91 civic hatchback, look at your ecu, if the red light is on permanently and wont go off, you need to replace the ecu. if its blinking you need to check which codes are flashing.