The injectors will have power on one side and its the PCM that sends a ground pulse [signal] to the other side. Did you unplug the injector connection and check for the ground pulse while cranking the engine or back probed while cranking or running? I would unplug the connection and check that way if you have not. If you still do not have that ground pulse then you should be able to find the same wires at the PCM and check for continuity along the wires for the two cylinders.
The ignition module sends a signal to the PCM which tells what injector to pulse. The ignition module also works with the distributor. You may want to look inside. Perhaps some strange thing happened to the relucor inside.