Hi Joe yes TuneECU is a very very useful tool. Definitely worth the few bucks for the cable from Lonelec.co.uk
Your problem could be a lot of things - check spade connectors on the coils for tightness, spark plug threads clean, how old are the plugs, spark plug leads crack free and no tracking happening, vacuum tubing crack free and all shoved up snug and tight, TPS might be dodgy but less likely on a Roadster, TPS/ISCV set correctly, did anyone ever remap the ECU, etc etc