I hinted in another thread that I'm getting a slight rough idle after filling up at a BP garage instead of the usual Shell (probably just coincidence) but after running Shell Nitro+ again for two full tanks, running through a bottle of Forte Injector cleaner and also changing the fuel filter it's still rough. We aren't talking major rough, but the slight vibration and pitch change is there. The sparks are brand new (iridium) and a service was done by me mid-May of this year (Oil, Oil Filter, Air Filter, Pollen Filter). RPM's all look normal at idle. Also, the strange starting problem is still there despite the fuel filter change, although it now tends to sound like it hasn't started and instead of suddenly firing into life it grows to life from silence instead. It really is bizarre. Any thoughts on the rough idle? I'm starting (perhaps hoping) that the two are related.