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Old 08-06-2008, 05:16 PM   #10 (permalink)
needs more cowbell
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It isn't that the injectors are leaky, it is that there is a layer of fuel on the inside of the intake manifold, it is a normal state of affairs.

That fuel is absolutely not usable if you "dry out" the manifold every time you kill the engine as the mixture is so far off there is no real useable power in it, and it causes the engine to stumble to a halt and it frequently relights when you didn't mean it to.

If you turn off the ignition, the engine shuts down right away. That fuel doesn't really go anywhere anytime soon if the throttle is closed and the engine isn't turning, so it is still there waiting for use when you restart the engine.

I do not know that oil dilution is much of a concern, I know planes would add fuel to the oil just prior to shutdown in winter and it would evaporate out when the engine is up to temp, and I don't know that much, if any, fuel is actually getting into the oil from sitting in the manifold between pulses.
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