quick update. borrowed a PCM from another engine to test with. tried mine several times and nothing, everything powers up but the PCM. plugged in the loaner and it fired every time and the MIL worked. tried it 20 odd times. it did not want to run as the tune is pretty radical on the loaner but it did fire and try to run every single time. plugged mine back in and nothing, no fire and no MIL. so looks like the PCM is dead. going to pull it out and open it up and see what there is to be seen but going to order a rebuilt one and have it reprogrammed.