Q: 02 Mitsubishi Lancer, no signal to injectors from ecm. Will the crank or cam sensor cause this? How do I check if it that or ecm?

You’re right in that the crank sensor (CKP) is the primary trigger for the injection pulse. But the only way to reliably check the CKP output is with a scope. If you don’t have a scope, all you can check is the internal resistance and that doesn’t tell the whole story. However, you may have made your problem more complicated by installing a used ECU. ECU’s and other modules in late model cars (cars made in this century) are mostly programmed to recognize the other modules in the car and will not operate when they find they are in a strange car. This was done to prevent chop shops from being able to sell off the modules in stolen cars. The only way to find if this is the case is with the factory scan tool. Some cars allow you to re-program the ECU. Others, like Mercedes have a much more involved unlocking procedure. If you still have the original ECU, I would recommend re-installing it to complete the troubleshooting. You can get help with this car by contacting Your Mechanic. They can send a technician to your home or office to check out your Mitsu and let you know what it will take to get it started again.