Just got back from Hyundai,

They say that the 2000 model old shape coupe you should be able to just swap the ECM over, the new one like I said kicks the starter motor in and turns over but won't start. So Hyundai gave me another ECM they had knocking about that was also only firing two cylinders and said to see if it would at least start.

It didn't, it does exactly the same as the one I got off the internet, which leads me to suspect that the immoboliser thing is causing me issues.

It isn't the coil pack I've checked it, the CKP sensor has been changed and it isn't compression or fuel injectors as far as I know. Basically I have proved it is an electronic fault as I know there is no spark on 2 and 3.

Hyundai quoted me £380 +VAT for a new ECM which I would like to avoid if possible but seems more and more inevitable however I have a plan...

I now have three ECM's one that starts and fires on two and two that dont start one of which I believe to be ok so... If I were to dismantle and remove the silcone potting on the PCB I could either change the transistors that I believe to be faulty, or take the immoboliser bit out of mine and swap it into the new one.

Circuit diagrams or advice please!