I've just replaced the rubber boot that goes from the air filter into the throttle and the pipes that go to the idle valve. Inside the throttle, where the big butterfly flappy thing is was a load of thick oil. There was also some at the air filter end.
Where has this come from? Is it normal? I'm wondering if it's come from the breather pipe.
I cleaned it out with some carb cleaner, do I need to do anything else? Can I use carb cleaner to clean the injection system? Does this have anything to do with the car idling at 1000 rpm sometimes? Not all the time, just most of the time.

Cheers

Ben