Welcome Dave, as Dave 'The Boss' says , its not that simple, but there are basics to check. Sensors are plugged in, wiring connectors are good. Earths are made. ECU's dont usually (unless your name is @IanK (Bagpuss)) do anything silly. So basics to start with. Also, if you have done short runs with overfuelling ( such as on cold start) Zetecs do fuel the plugs and can run like dogs. I found the best way was to always replace the plugs. They are about £15 for platinums, so cheaper than a coil pack. Also, zetecs are prone to earthing sparks down the porcelain, so a tiny bit of silicon plumbers grease ( really, just a tiny bit) with insulate and make the spark go into the plug. Coil leads can be an issue as well. So, we have avoided any complex computers so far with just the basics.