Car - 1984 KE70

motor / part in question - stock 4age Silver top 20v + Razorback ECU and loom

problem - Cylinder 2 not firing.

-When plug lead from cyl 2 is removed from plug it fires a blue spark (strong??).

-When plug lead for cyl 2 is removed when engine is idling, nothing changes. When any of the other plug leads are removed when idling the engine slows to a stall.

-No timing mark seen when timing light is attached to cyl 1. No ignition signal when timing light attached to cyls 2 and 3. Only signal on 1 and 4. When the timing light is placed on cyl 4 lead I can see the timing mark at 15 degrees BTDC at idle.

-Static timing (CAS, crank and cams) all ligned up perfectly.

-Plug leads checked. Problem persists when leads are on different cylinders.

-Plugs (all of them) are black and smell like petrol (over fueling??)

-People have suggested it could be a valve issue or a compression issue on that cylinder. I have checked all of the vaccuum hoses on the ITBs. Everything is where it should be. Engine idles well, revs up okay (only bogs slightly). Someone also suggested that I check that there are no clogged holes in the throttle body for that cylinder.

occurs/started when (if applicable)- has been happening since i got the motor running.

Any help would be much appreciated

Kind regards,