Originally Posted By: ford46guy
Originally Posted By: Kestas
Originally Posted By: ford46guy
He felt it is very important because when you idle you may use more gas if it is dirty.
Unless it is idling rough, I doubt what he said is true. Deposits can restrict the throughput of air into the engine, not waste gas. Deposits will force the idle air control motor to admit more air into the engine, until the IAC is maxed out. This is a problem chiefly at cold idle in gear with the a/c on. That is when the engine requires the most air during idle.
I clean with gasoline, since it should be compatible with all materials in the area and not harm the throttle body.
If dirt holds it open a tiny bit then more air = more gas?
It would need to add more gas to keep air/fuel mixture proper. It might not like it, if it thought the correction amount was too wrong, too different, too far from what it thought was zero on the flap. It should know how much air is going in from the MAF, and will touch up as the O2 sensor indicates.
I'd think rough idle is not from the flap being stuck open but rather rough airflow over the edge of the valve, turbulence perhaps, or the fact that "idle close" keeps changing position after every throttle opening. Or that the valve is slowly finishing closing, or is otherwise moving very slowly due to the crud moving around.