TBI rough idle

[jezzathep]

My throttle response query was a little abstract; hopefully this is more straightforward!  

My TBI has a slightly rough idle. It seems to miss a little, most noticeable when warm. Seems it should be perfectly smooth so I find it rather distracting.

So I did a service after I bought the car:- oil, filters, plugs, cleaned sensors, pumped the engine full of CRC GDI cleaner. But this didn't seem to make any difference. It's a low km engine and the car runs perfectly otherwise, no error codes.

I'm thinking in order, vacuum leak, injector leaky or dirty? may be carbon build up?? Thought's?