You might try to look at why it got fried first, or you might have two dead cars. If it is indeed fried. Your idea is good, but I wouldn't use the ecu from my other car. Others here can prbably assist you in checking out the fuel injection in detail. They don't have a high failiure rate. However, a bad warm up regulator can cause the symptoms you describe. With CIS it's all about fuel pressure.