From what i gathered from search and pics, the IACV is hooked up via a tee which connects to the air regulator than into the intercooler piping before throttle body.

does it matter where you plumb into the piping? why does the air regulator idle correctly being hooked to intercooler piping and dont idle correctly just sucking in air not hooked to nothing.

thanks for taking the time to read.

Off the coldpipe (IC piping before the throttle body) connects a T that connects at one end to the IACV/AAC assembly (goes under the intake manifold and comes up the head side of the manifold to the IACV/AAC) and the middle of the T goes to the Air Regulator (cold start gizmo that lets in more air when cold and closes off as it warms up).

IACV/AAC is bolted to the intake manifold, and air from this just goes straight in. Air Regulator has an inlet (from the T) and an outlet which goes to the intake manifold via a large diameter (5/16" ish?, its the only big one there) pipe which just goes traight into the intake manifold, it's right behind the throttle body.

See Section 148.(there's a note here that says to see Section 111 but that actually goes to the IACV/AAC module, which is partcode 16250N in the diagram; Air Regulator is 22660M)

All air going into engine MUST MUST MUST be metered.

Also, because it is turboed, if it's not connected to a high pressure source on the turbo side of the throttle body, when under boost, air will be pushed out of the plenum in the reverse direction through the IAC.

Simple really.

Wow, you guys covered it, I have nothing to add. Thanks guys!

This is why i love nico club, knowledgeable people like you. i got the bung put into the pipe today, then teed the iacv and regulator. started the car and BAM!! THE SWEET SOUND OF PERFECT IDLE. had to adjust because it rose to 2000 rpm. no more tapping the pedal for 2 min until the temp rises. thanks again and ill be back on the road tomorrow.

Congrats!

Speaking of which.. if you're idle air stuff is toast what can you replace it with?

I can't idle when cold unless I manually keep the gas slightly on and I'm slightly tired of it

I get perfect idle, I just run hella rich at cold idle. I replaced my air regulator with a brand new one, as well as the temp sensor. I have also cleaned my IACV...

I too am tired of this. BUT I have perfect steady cold idle. Just if I try to gas it more than 20% when cold, it bucks and pops...

Yeah me too same as rico when cold.. perfectly stable, but more than slight throttle and it gets unruly..

Tho, it doesn't help I've got DSM injectors with a halfass rom "tune" that's never seen a dyno, so I'm running "slightly" richer than I should be across the board

I still get 25MPG mixed hw/street

biosehnsucht wrote:Yeah me too same as rico when cold.. perfectly stable, but more than slight throttle and it gets unruly..

Tho, it doesn't help I've got DSM injectors with a halfass rom "tune" that's never seen a dyno, so I'm running "slightly" richer than I should be across the board

I still get 25MPG mixed hw/street

Hah same as me

I get a weird lean condition when I give slight throttle from idle though.. after that it's rich to the moon!

aargh! i spoke too soon. just replaced my acc relay under the hood, because the shop lost it when they pulled the body harness back into the engine bay. 21.00 later i have heat again and blower. SWEET! but then i go to start car and idle is low with heat on. i went to adjust idle with little screw under throttle pulley and it broke off. is there any easier way to adjust idle besides iacv and tightening throttle cable? i cant seem to dial it in it idles intermittently between 850 and 1050. anyone?

Check your throttle position sensor.

As far as idle dropping when electricals are on.. thats normal, but if your alternator is on the way out or weak battery (usually one causing the other or vice versa) it'll be worse. Also, improperly adjusted idle stuff will keep the ECU from being able to compensate, or if your engine is just running like *** (i.e. ECU has to open idle controls full open because your base fuel pressure is so high that even at idle pulse widths the fuel injectors are overfueling and making it run badly and therefore low RPM)

Read the FSMs people! And don't just glance at what you think is relevant, READ THE WHOLE THING! ITS YOUR CA BIBLE! Or at least read the whole EF&EC section as thats what most people are having problems with..

You don't adjust idle with anything on the throttle body!

Only adjust it using the adjustment screw INTENDED for this purpose on the IACV/AAC !

The throttle cable should be adjusted tight, but not so tight that it sticks open or is super twitchy (i.e. the pedal vibrating should not cause the engine to surge on its own). The throttle cable is NOT AN IDLE ADJUSTMENT METHOD, and anything else on the throttle or TPS should NOT be messed with unless you ALREADY SCREWED IT UP and need to fix it, or it was way wacked out somehow and you're attempting to fix it.

My cold idle is up around 1200 or so, sometimes more if its really cold, warm its about 800 or so.

Leaks, sensors (MAF, coolant temp, throttle sensor, knock sensor), and properly working idle-related gizmos (IACV/AAC, cold start Air Regulator, throttle body) are important to properly behaving idle, check these things. And make sure your fuel pressure is correct to (SEARCH the forums, and set it with engine off, fuel pump on!)

Everything Bio said is dead on. The biggest thing is that if you had read the FSM you'd know that to adjust the idle, you don't use the screw on the TB, but the screw on the IACV.

i know fellas, read the FSM. UNFORTUNATELY my work laptop dont have enough ram to support pdf files so i usually go to my parents every other week and print out a chapter at a time. sorry, but thanks for your help. i really do appreciate it. im goin to mess with my car tomorrow. i did not set idle to proper settings at cold. i thought it was supposed to be at 850 rpm's right off the bat. ill set it around 1200 cold. i have a brand new optima battery and the alternator is reading fine.

You are right once again, did a check on the alternator and it tested bad. GREAT, i knew something was up when i turned on my headlights and interior lights and the idle went to ****. Good thing there is a alternator rebuild shop 25 miles away. this should explain all my symptons.

reputable rebuild shops > 'new' from parts store (even if you could get the RWD alt..)

place I had mine rebuilt at rebuilt it a second time because something that had appeared fine at first died a month later so they did it under warrenty, no charge to me, fixed in about an hour. (drop off alt, go eat, come back..)