it doesnt seem to affect it mechanically?

is this true?

well, then would it only be serving and anti-icing role?

Q: can i operate without the coolant lines to the IAC valve?

tia,

t..

 

...nope, it doesn't HAVE to have coolant flowing throwing it. It's mainly there for cold weather climates, to warm up the throttlebody and keep the TB plate from sticking.

I bypass mine (I dont live in a cold climate zone). Why? it just to makes it easier to swap manifolds whenever the need be. But you can bypass running the coolant to the IACV.


[Modified by Katman, 9:35 PM 6/6/2002]

 

thanks man,

thats all i needed

t..

 

np.

 

ok well since this was already a post, i dont wanna start my own, i by passed my IAC, my car idles at about 1000-1500 up and down up and down, i unplug the IAC and boom 500 perfect ilde purs like a kitten. anyways i was gonna ask whats your guys opinions on how to get itto idle like the IAC is unplugged. Help please

 

so:

did it idle like that b4 the bypass? does it idle like that when cold?

BUT:

if you unscrew the brass plate on hte back of the IAC and check that the plastic thingy inside is not loose - this may help. (you can screw it back in)

also:

no, actually thats all i have...

HTH,

t..

 

it does not idle like that when cold, and yes it did it before the bypass but i always thought it was due to the secondaires not being hooked up. this is all on my Skunk2 intake manifold now. thanks for the help!

 

It sounds like your talking about the FITV [when you talk about the brass ring, that is], which is the Fast Idle Thermo Valve, which is NOT the Idle Air Control Valve.

The IACV does not 'need' the coolant lines, nor does the FITV. However, the FITV uses coolant to heat the wax plunger which in turn seals off an additional air way which was helping out to raise the idle in cold start conditions. If you remove the coolant lines to this, then you should open it up and screw the plunger in so that the air way is ALWAYS closed. If you don't do this, you get a nice hunting idle because the ECU can not compensate for all this additional air from the FITV.

If I'm wrong, someone wanna correct me?

 

opps!!

thanks Chris

t..

 

ok some rookie stuff but where is the FITV

 

most of the time its right under the tb.im pretty sure all obd2 cars dont have that valve anymore. another good way to bypass it is just make a plate to cover the bottom of the tb where it mounts on too.So far works really good for me.

 

i think only obd 1 (0?) automatic cars have i the FITV. My 91 has it. Maybe to keep engine from dying as you put it in gear cold??

 

nope i have a 98 integ obd2 and i still have the fitv.

 

is it an automatic???

 

So if you live in a cold climate you should connect your coolants lines to both the iacv and the fitv?My idle fluctuates up and down.I'll run coolant lines through it and see what happens.Also im getting a CEL for the iacv.i tried two other iacv's and im still getting the light.What could this be?Thanks

 

I would just connect them up. The FITV needs coolant flowing to it, otherwise it just won't work as designed [its an all mechanical valve].

If coolant is diverted from the FITV, you need to open the valve up and screw the brass ring down so that the plunger is fully seated and will never allow additional air to bypass, otherwise you will get the dreaded hunting idle from all that 'unmetered' air entering the intake.

 

The IAC has coolant running to it so it can control the fast idle speed of the engine until it warms up. Then, the valve closes and it should stay closed until the coolant temp drops to "cold."

If you're getting a "hunting" idle, it may be because the cooling system needs to be bled. An air bubble in the coolant under the IAC will cause it to open and close as the bubble moves around. Replacing the IAC isn't going to help as long as there's air trapped in the cooling system.