How did you install the DCCD wiring? Did you cut the ECU wires or strip the insulation & wrap the wire around? Solder or crimp?
The other possibilty is you may have knocked a connector off when doing the clutch. Yours is an auto to manual conversion so there may be something there you knocked, eg, something to tell the ECU the car is in neutral. An auto will turn over but not start when in gear.
I'd be looking at something wiring...a loose connection somewhere