Rough shut off...

[PoisonDrop]

Every once in awhile when I shut the engine off it's real rough, like kind of a hiccup. It's like the engine runs for one more rotation and then shuts off. It only happens maybe once a month.

Today I had just filled up with gas. I drove home from work (maybe 10 miles), and shut the car off, and the same thing happened. I tried to restart to check it out and it had a hard time starting. When it did manage to start, I noticed that I had lost almost 1/4 tank of gas! Subsequent starts and shut offs were all normal. Just happened once.

So I have no idea what may be the problem. If anyone could point me in the right direction, I'd greatly appreciate it.

Thanks in advance.

[Mi|<E]

This happens in some newer cars that ive read about. Its called
the 'Atkins' cycle or something like that. What is happening is
some unburned vapour is igniting causing another rotation like
you expected. Im not sure how to remedy this but it does no damage
to the car.

Loosing 1/4 tank of gas would be nerve racking, thats
10 Liters? The volume of 5 big bottles of coke somehow made its
way out of the car, thats alot of coke! Id give the fuel lines
a nose check if it happens again. Or by chance did you take a
tight corner? That causes the fuel needle to sometimes go
down or up by as much as a 1/4 tank. Mine is slow as molasses
to get to full when I fill up.