Originally Posted by swamp2
I've heard the horror stories from a few models. However, the number of cars and models using this is HUGE. For example every V6 Ford Ecoboost has DI. I suspect it was somewhat of an isolated incident(s).
Every manufacturer's implementation of DI is different. Carbon build up is a big problem for some cars and some manufacturers. This is also dependent on which country the gas is from and how it is made. US gasoline has a high amount of sulfur that isn't present in the gasoline from some other countries so DI has no problem in those places. The key is to come up with a reliable DI technology that works in all car markets. I believe the M3 doesn't have DI because they wanted to have maximum compatibility and reliability in all markets the car sells in.