One thing to check before anything else is done. Need to find out if the ECM is actually running from the PROM, if it isn't, then the engine is flooded due to cranking.
Do this: observe the CEL, and do a key-on, engine-off. The CEL should turn on briefly, blink off, then turn on solid. Can repeat the test after a minimum of 10 seconds of key-off.
The blink off is the key, if it does that then the ECM is running from the PROM. If this case continue with the other troubleshooting.
If the CEL just turns on solid, the ECM is in limp mode. In this case do not crank the engine over. The ECM will open the injectors for twice as long as they need to be and flood the engine.
Again, in the case that the CEL just turns on solid (no blink), remove the PL board. Then try the test again. The PL board can shift and lock up the ECM.
Once the CEL does the blink off it would be best to replace the spark plugs. Or, if some cranking doesn't start the engine, hold the go-pedal to the floor while cranking. That is a clear flood mode.
RemoveBeforeFlight