Hi Ian,
You need to sort the running issues you have first, do you have diagnostics for the ECU? If you are struggling I have Rovergauge and an emissions tester.
Check the following,
Quality cap leads and rotor arm from Powerspark ignition
Correct tune resistor fitted?
Engine timing
Air leaks
Coolant Temp sensor (from the rich running this may well be the problem)
Stepper motor cleaned and the plenum airways cleared
Base idle
14CUX will run decently in most applications on the factory maps and is really only upset by very wild camshaft changes and superlight flywheels. Unless you have spent a lot of time and money making expensive upgrades then the problem most likely lies with a faulty component or incorrect setup of the injection system.
Let me know how you get on, happy to help out
Steve