I need to make this engine turn off when it runs out of fuel

Currently my engine has a fuel light and works about as well asI can make it without it including something like:
(dramatization, duh )
How would I go about doing this?

@massey101
Thank you.
@Ace
Fuel goes in, fire and smoke come out. Can it be more simple?

@cinebox
Well, besides it being a necro after I deleted the save it's nonexistant.