possibly IACV, high idle

[tramp_drift240]

I removed and cleaned out my iacv steez, which kind of helped my idle problem, but i still had to screw the adjustment screw all the way in for the idle to drop to around 2-2500 rpms.

then, while trying to diagnose whats going on, when i take the iacv hose off of my intake piping and plug it up, my idle drops to a little bit over 1000rpms.

what's this mean? what am i supposed to do next? i was out on a test drive with the hose plugged, and it was just dandy for half the drive, then it started to idle around 1500-2000 rpms.

i want my idle back down to 650-750 rpms.

[Hijacker]

Was it that high before you cleaned the IACV?

i would look for potential vacuum leaks on the manifold

[tramp_drift240]

it was around 3000 before i cleaned it, then it was down to about 2500.

leaks on the manifold itself, or leaks on the intake before the throttle body.

[srpowered240sx]

it was around 3000 before i cleaned it, then it was down to about 2500.

leaks on the manifold itself, or leaks on the intake before the throttle body.

both, check the intake mani gasket, all the hoses, tb gasket.

[tramp_drift240]

awright, the manifold to head is super tight, and the gaskets new.

upper to lower is super tight and new gasket.

throttle body to lower manifold is super tight and new gasket.

ive only got the valve cover hose and the IACV hose from the intake piping, and the TB to intake, intake to MAF, MAF to adaper, adapter to filter are clamped to the max.

anyone have an easy way to check everything for leakiness?

[tramp_drift240]

still having trouble finding any leaks.

whats the purple plug on the IACV for? i found that unclipping it kept the rpms lower, as if the iacv hose was plugged shut.

could the IACV valve just be bad overall?

[boriquaS13]

Try some carb cleaner spray it around the gaskets where they meet the cylinder head etc. also spray it on and around the vaccuum lines if there is any change in the idle (idles higher or rough) you have a vaccuum leak in that specific area. If I remember right you just put a head gasket on correct, was there a problem with the idle before the repair? If not it has to be something you did or missed (or pure coincidence). Hope this helps

[tramp_drift240]

yeah, i just recently replaced the headgasket. and i was having high idle problems before that as well, basically ever since i got the dual cam into my pignose.

should i really use carb cleaner though? isnt there something thats not so...good at eating away at things to use? haha. i dont want to spray it in certain areas and end up having my gaskets turned to rubbish.

do you think i could just adjust the screw on the throttle body? i was messing with it some before i did the headgasket, so maybe i screwed it up.

im just really tired of sitting at 2000rpms at stoplights.

[vancouverbc]

what is your idle with the iacv purple plug unplugged? how about when you squeeze the hose that branches off to go to air regulator? adjust the screw on throttle body so it is plate is as closed as possilbe without binding. unless you have ac on , that purple plug should not make any difference.

[tramp_drift240]

i was waiting for you to reply vancouver, i was reading that big iacv thread with you in it.

i removed all my ac stuff, and its never on, but with the pruple plug unplugged, it idles around 2-2500rpms. idles the same as if it were plugged in and the hose from the intake were plugged.

with the purple plug clipped in, and the iacv hose clamped to the intake pipe, it idles around 3000+, which sucks.

the iacv adjustment screw is all the way in to keep it around 2500 with the hose plugged.

ill play with the throttle body some tomorrow, see if that helps any. keep replying with ideas to help me out, my idle is my last big problem to deal with until i can drive my car on a regular basis.

[vancouverbc]

have you had your injectors out? damaged o-rings will cause high idle. i would individually unplug the o2 sensor, tps, maf, and coolant temperature sensor to see if that lowers idle.

[tramp_drift240]

injectors havent been out since i put 'em in summertime.

how can i check if its the injector orings?

and you mean one at a time, unplug each of those to see what happens?

[tramp_drift240]

replaced injector orings following vancouver's write up, i believe.

then i adjusted the idle screw on the throttle body, which helped some.

but it still idles around 2000 with the throttle body adjusted some, the iacv adjustment screw all the way in, and the iacv hose plugged.

with the hose hooked up to the intake like normal, itll idle somewhat normal, then as soon as you hit the gas, itll rev up to around 3.5 or 4 and stay there.

[RCG_Savage]

Wow you have the same problem as me my TB shaft was bent and scraping the housing on the inside, replaced it same problem. I have cleaned the IACV as the idle adjustment was completely gunked up, checked my harness and parts and still nothing. I can't figure out this problem however unlike you my KA has had this problem since I got it running.

When I plugged my IACV line I could get it to idle at a 1000 iirc but like you said the second you hit the gas it would rev up. I wonder if the IACV unit might be toast. Could the air regulator have anything to do with it?

Do you know of anything that might have happened before your idle got screwed up?

Another possible chance is that the air regulator has been clogged or stuck open I'm thinking since I have cleaned the IACV the AR is to blame
Modified by RCG_Savage at 3:58 PM 3/21/2008

[tramp_drift240]

nah man, ive been having the idle problem since i got it running after my dual cam swap. it just hasnt been til recently that ive been trying to correct it.

ive got it at a steady 2500 rpm idle when im sitting at a light/stop sign or whatever. sometimes it gets annoying though so i ride the clutch a little in first to drop the rpms.

on a better note, when im driving down my street (25mph), i can just pop it in fourth and the high idle will keep me going at 25-30mph.

any help anyone?

[USMCgetsome]

check your wiring or resistance values of the solenoids or pinch the line to the air regulator. I have the same issues like you guys. But mine had some hints back in the day i'd idle below 1000 and i'd hit the a/c and it would go lower then come up to 1200. I just took apart my iacv today and the solenoid part was gunked. I did a resistance check on the solenoids and mine are in range. I'll post up my findings later on today. Waiting for the rtv to set. Next thing to do is get a squirt bottle and some soapy water and look for leaks!

[guitargod240]

this thread is almost 3 years old i know lol. but.....mines doing same thing will keep going by itself cuz idle will keep cars momentum up and its not as high as anyone else's. it did it b4 and then an injector crapped out so i replaced it. now its doing it again at 1000-1200. if i sit for a min tho on a flat surface like for 10 seconds it went back to 750. it happened 3 times earlier. so idk any ideas would b greatly appreciated. i have yet to touch iacv screw cuz just started i havent done anything yet. looking for opinions quick and gonna screw with it tomoro. thanks.