This is something I noticed- If you turn the key and one click. The electrical activates, the gauge panel lights up, if you wait about 3-5 seconds there is a click/tap. I was told this is the injector unit pressurizing. I do this and I never have the engine stutter, but when I don't do this I get the stutter. So that little waiting before I turn the engine over and it starts stutterless...I'm not sure why or how but that works for me-