Bad coil is usually bad period. It doesn't know when the car is up to speed or not. If it causes a misfire its going to misfire all the time.
Why do you think its not injectors?
If you have access to an inferred thermometer let the engine get up to temp. Check each cylinders exhaust temp. They should all be very close. If you have one cooler start there.
Pull the plugs, the cool one should be black, and maybe wet compared to the others.
Switch it with another cylinder, recheck the temps etc.