jweller

Ok I think I've got it figured out by looking at the helms but let me run this by everyone so I know if i'm right.

the IAC valve is similar to a choke on a carbed car. it is open when the car is cold, allowing more air to get to the engine. when the car warms up it closes. it knows when the car is warm because of the coolant running through it. if the valve is open, the car idles higher. Is this correct?

now, heres the thing. I was doing all this other work on the car and I figured I'd do the coolant bypass for the TB. then I started looking and I realized that the IAC valve has coolant running through it as well. figured I'd bypass that as well since it's in the same area, must add a little bit of heat to the plenum. I ws gonna just cut a new TB gasket and block off the passage that leads to the IAC valve and deal with the shitty cold idle.

Am I an idoit, a genius, or just high on fumes from the garage?

Stew Pidasso

The idle control valve is a solenoid operated valve that lets air by-pass the closed (at idle) throttle plate, thus allowing the car to idle. Idle speed is adjusted by the computer by opening and closing the valve.The coolant flows through it so that fuel doesn't condense and puddle in the intake manifold when its cold out. When it's warm and the engine is up to operating temp, it just adds heat to the intake charge (bad).

RaceTilIDie

Yes! You descriped more how the FITV works, Stew desribed the IACV.

jweller

OK so I'm good to bypass the coolant to it then, right?

RaceTilIDie

You can try it. When it's really cold, the car may idle rough during warm up. I have mine bypassed, but I live in San Diego, and it's in the 80s now, so I never see cold. It's 7:30 PM right now and it's about 70 degrees.
http://www.accordinglydone.com/tech.php?ID=9


[Modified by RaceTilIDie, 3:47 AM 1/4/2003]