IACV problem... i think?

[19dabeast85]

Your IAC valve itself may be bad, introducing a "vacuum leak" into the system. One side of the IAC has direct access to filtered air from in front of the TB, the other side lets air into the plenum in tiny increments to adjust idle (I'm sure you already know this), but if the valve is stuck and not closing all the way, or is sticky/jumpy while adjusting, it'll cause surging. Think of it as a "bad section" in the IAC's infinite range between CLOSE and WIDE OPEN. It sticks at this bad section and jumps across it, letting in too much air, then tries to correct and jumps back down across the section, limiting air. This continues producing up/down idle surging. At least this is how I understand the operation of the IAC.

Pretty sure I'm in need of a new IAC also, I've got a brand new OEM FITV which took away most of my idle surging, but it still happens occasionally, only device left is the IAC.

[Shehzada]

One more thing to try:

Disconnect the TPS and see if the surging goes away. (The CEL will come on).

[KeeleDesign]

no the tps is fine,

it surges it's butt off when disconected. lol, thats how i knew it was fine.

[and1jr17]

I wanted to suggest taking throttle body cleaner or carb cleaner.. with the engine started, and spraying around.. especially where the manifold and head meet, this would be to eliminate a manifold gasket failure... just spray vacuum lines and around where they go to... and if you here the idle in the engine lower.. that means you have a vacuum leak where you sprayed...

[and1jr17]

no more surges, no more coolant isues, cleaner look for the manifold

I was just curious as to how this effects your emissions if any at all.. and how about cold starts?

[KeeleDesign]

it was the iavc.... some times it worked other times it didn't. i did do the crb cleaner gasket test. i have no leaks, doesn't surprise me.
every gasket i put on i also put a high heat atv gasket sealer on both sides of the gaskets, this goes for almost everything, including the valve cover, and the valve cover washers lol.

I do not like leaks, and by goodness if my tranny seal isn't leaking like a sob. and i wasn't the person who replaced it.

[f22a4boy]

what is the IACV and where is the idle screw i justed fixed some of the idle
with timing gun but now it surges so could be the idle screw

[ECalvo31]

Good info!

[HondaFan81]

keele, keele, keele,

take out the plenum and fill all the air holes in it remove the iac and all the sensors connect the iac and adjust idle with the screw

i hate idle problems so i eliminated them

Everyone keep in mind, this guy is from Florida. Heck, they probably don't even know what the freezing point is. What he says applies only to environments similar to his, otherwise keep your IACV and FITV minimal.