Coil driver outputs on the ECU are fairly easy to check with a diode tester, mine reads 0.514 when GOOD and reads 1.2 when duff.

A wrongly set or faulty TPS would make low speed running and stalling very likely ,,so its possible that could also inhibit starting , also s4 is very battery sensitive they need a full charge

you dont have to splash out on Ducati coils Honda Cbr600rr coils fit and can be picked up much cheaper .

Happy Days, bike runs again after fitting another ecu, this time a stock one, together with its associated immobiliser (both used items) and the matching key.
So, the bike will fire once if the ecu is not compatible. The immobilser light was going out in 0.7 seconds so the key was recognised but the ecu didn't like the "racing" ecu supplied with my used Termi's or the flashed one I had borrowed. The original ecu I confirmed faulty using diagnostic software. It was "seeing" sidestand down and kill switch off even though those circuits/switches were fine.

So, when you think you've tried everything......go back to the original thought!

Thanks guys for all your inputs and interest.

Check the version numbers on your ECU - I expect the one that works was a 59M and one that didn't was a 5AM and the wiring loom/pin out is different between the two; the sidestand is the giveaway I think!

All 3 ecu's were 59M.... The original one was the one that sensed sidestand and kill switches in wrong position and appears an internal ecu fault. That one would consequently not allow any spark or injection.
The other 2 ecu's which allowed one spark/injection appeared not to be communicating with the immobiliser although both were meant to be immobiliser disabled. Incidently, the immobiliser appeared to recognise the key as it extinguished the light iun the correct 0.7 second.
Cheers.

Happy days. :)