Today I decided to change the CTS since it is fairly cheap and the resistance values accross its pins were slightly different to each other. This did not change the cars behaviour at all, hesitation at 2000rpm is still there.
Thanks to saumil I have the ECU pin-out and KE system test procedures so I dabbled a little. First of all I checked the harness to air flow pot, eha and CTS for continuity, all were fine. I then checked the air flow pot as saumil recommended, at rest it is around 1.4kohm, rising quickly and then more slowly until about 9kohms before falling again so no problem there.
Now onto the EHA valve, this passed the resistance test however I never noticed any enrichment whatsoever, it was always at 0ma, KOEO was 0ma too but I believe this is correct as mine is a standard non-cat car. When I had my fuel distributor rebuilt the gentleman checked the EHA and told me it is fine and working as it should be. I can only imagine I have an ecu fault. I have a spare EHA which I performed the quarter turn clockwise trick on, I swapped them over and this was also drawing no current at all.
I noticed one other thing, with my aircleaner assembly removed when I revved the engine white smoke, smelling of oil came out of the hose which goes from the valve cover to the air cleaner. I can't remember seeing this before, but the car still runs okay/no hesitation with the CTS and thus KE-Jetronic system disconnected. Where from here???