Re:Idle air control valve
 

...o2 sensor fixed the up and down idle in by buddies car....

Re:Idle air control valve
 

*update* yup i finaly got my idle to normal again. that used iacv worked. you have no idea how happy i am ;D ;D ;D ;D no more of that reving bullshit.
so if any of you guys have the problem that i had. i would definatly recomened the (iacv) but make sure its for your exact engine :P

Re:Idle air control valve
 

ok, My car will not idle under 1000 RPM (or my autometer tach is messed) it usualy stays at 1000, and 1500 when warming up. But on occasion the tach needle will shoot to 0and then back to 1000, and the idle will surge. Sometimes it's so bad that unless you keep your foot on the gas the car will die. other times it's fine and the car(89zc, 91 ecu) is completely normal

Re:Idle air control valve
 

I forgot about this thread, ... i finally took pics of my jbwelded TB:

http://www.ecimulti.org/albums/album...0001.sized.jpg

http://www.ecimulti.org/albums/album...0002.sized.jpg

my preferred method of shitcanning the FIV :) working on many many cars...

Re:Idle air control valve
 

ok, my idel problem is a little higher.Most poeple say theres jumps (500-1000, or 1200-down) On my car its stuck at 2800.I've takin off the ICVA and cleaned it with carb cleaner,but it still shoots to 2800. I also sprayed soapy water on all the VAC lines and didn't see no bubbles. Is there a chance its still the IACV or should I be looking somewhere else? This is in a 88'crx w/B16A ;)

Re:Idle air control valve
 

It's fixed. It was the FIV or FITV. Took it apart and cleaned it. Car idels fine now ;D

Re:Idle air control valve
 

toss your fiv's... nothing but trouble.

Re:Idle air control valve
 

I finally fixed the idle on my CRX!

Symptoms: Stumlbed on idle alot, almost like it was mis-firing on cyl's. Engine's RPM never stayed constant. Just sounded like complete POOP!

Solution: Replaced ECU, Idles 100% better, and even sounds better when I rev it up.

More or less I took my multimeter (digital volt meter) and a honda service manual and followed the flow chart for diagnosis. Evetually got to where it said to substitute known ECU and that worked!

just thought I'd let you guys and gals know not to count out the ecu.

Re:Idle air control valve
 

also, if the butterfly valve isn't closing and sealing all the way in the TB it will mess with your idle

had that prob a long time ago on my old rex. new tb fixed it right up

Re:Idle air control valve
 

Today I finally got rid of my code. Just put the right plugs on the right sensors. It helps if you look at a diagram and what color wires go where. I got smart about it. But I still have an O2 code. one left. Maybe my car won't run like ---- when I get it fixed.

Re:Idle air control valve
 

ok, warm up idle is 1500, when it warms up, it will kinda of surge, go from 1000, to almost dead, then back again about 4 times till it dies. what should I check? my car doesn't idle and is pissing me off. please help!!

Re:Idle air control valve
 

try checking out the tps too...

Re:Idle air control valve
 

My man here is right, What you really need to do is disconnect the plug to the iacv when the car is on and see if ur idle steadys out... if it does then clean the sensor up or replace it, you could also have a tps problem or a vac leak. However i wouldnt mess with the idle screw at this point as i dont think this is ur problem

Re:Idle air control valve
 

hey guys i just put a new b16 with greddy turbo kit in my 92 hatch i have a problem where my car wont idle at warm or cold. every so often it will idle really low and go up and down very slightly then die but mainly it wont idle at all. i have a 00 si tbody so i dont have a fiv valve i dont get a check engine light. when i unplug the iacv valve it just dies. i used all new vaccum lines when i did the swap and ive checked them all over. im using a p28 ecu. the car runs great accept at idle. ive tried adjusting timing and the idle screw and it really didnt help either way. if you guys have any help let me know thanks bryan

Re:Idle air control valve
 

I didnt read all of the posts before, but heres how I fixed my IACV. wait until the engie is cold. Unbolt the IACV but DONT take it off. You might wanna disconnect the sensor, it just makes things easier. Get a pop, soda, coke, beer whever you want/whatever you call it, can. cut it so you have about a 3'' by 2'' rectangle. make sure its clean. place the can between the IACV and the intake manifold. it will take care of your problem. (its workin for me) it bacially bi-passes the IACV. you may have to re-adjust your idle elsewhere, but it works!

http://www.villagephotos.com/viewimage.asp?id_=8740435

Re:Idle air control valve
 

I had a problem with the idle thing too. There are a couple of ways to fix the problem... or at least that worked for me. If you just want to ignore it and live somewhere warm a majority of the time, you can unplug the sensor on the iacv, put half a paper clip in there, wrap it up with electrical tape... idles perfect all the time after that. But if you actually want everything to work, you can try taking off your radiator cap and start the engine and let all the bubbles out of the radiator , or until the engine gets warm, (this worked on my friends rex)or you can get a new alternator if that doesn't work. I got a new alternator and it went away. I read up on some different forums to do that, and so I did and it worked.

Re:Idle air control valve
 

Ok, i have a stumble on my idle, i dont have the FIV hooked up, so its not that.

But its hard to start!! I mean it will start the crank later, im going to try and clean the Iacv, isnt that the eacv?? the thing on the back of the manifold? or is it the one under the Throttle body??

Thanks!

Re:Idle air control valve
 

after i did my swap, my motor would rev itself at idle. it was the iac valve and it DID NOT show a check engine light. all i did was pull the iac off and clean it with brake cleaner and i haven't had a problem since ;D

Re:Idle air control valve
 

i had a erratic idle jumping from 1500 to 3000 all the time ( cold and warm) and found out i had forgoten a injector seal on 1 ... if that helps recheck these if you changed them...

Re:Idle air control valve
 

With my zc if I switch between chips, like a stock pm6 to turboedit pm7 then I get the idle surging effect. So what I do is let it keep surging, turn the idle screw in slowly until it stops surging.. I have to change the base idle everytime I switch between stock codes and turboedit ones.

Re:Idle air control valve
 

the same thing happened after i did the bypass on the hot water line going to my acv.. it annoyed the ---- ---- outa me only at idle it would go up and down...

Re:Idle air control valve
 

your IACV will cause lots of annoying crap! For instance my IACV is F'ed up... cold the car would bounce from 1200 to 2500, with a check engine code which I believe is #44, then once it got warm it would idle 490-520. what you should do is stick a staple in each side of the little blue service connector hidden up inside behind your glove box, and then turn the ignition to on and count how many blinks your CEL does, LONG blinks mean 10, and then short blinks are 1 , in a civic I believe it's #44 for IACV, if thats what the problem is foresure then take it off and check out the figure 8 o-ring, if it's flattened out then it may be a wise choice to get a new one seeing as how Honda will probably only want $1 or $2 and hopefully that will fix it, HOWEVER....... if it dosen't then there is a way to ADJUST it by turning a little 5-point allen bolt on the side of it. Now if that dosent work then it is probably seized up inside so what you need to do is, sneak into your sisters bedroom and steal the $2.50 that she's got hidden under her pillow and has been saving up from Whoring herself out, go to your local Gun & Ammo shop and purchase some shell's, go back home borrow your dad's gun and shoot the ---- out of that damn IACV thats been giving you so many problems. (hey, if nothing else you'll feel alot better!)

Re:Idle air control valve
 

I havent read this whole post but

alot of my idle issues were solved by PROPERLEY resetting the ecu. that is, letting the engine warm up, pulling the fuse for 30 seconds, then start the car and let it IDLE for 10 minutes. then shutoff car and restart.

Re:Idle air control valve
 

I had a similar problem not too long ago.

My idle was around 2200 steady at all times. I just replaced my IACV with a used one and idle is back down to about 1050-1100. The only problems I have now with it is at cold startup my ilde doesnt go straight to the warmup idle (1500-2K). Instead it stays at warm idle fo a minute or so until it warms up slightly.

Basically IACV fixed my probelm though. I looked inside my old IACV and the blue thing inside it was all torn up looking.

Re:Idle air control valve
 

once my idal was boging and and the headlights would dim when I steped on the brake, all that I did to fix it then was tighten the battery wires and made sur I had good ground on conections. I FUCKN HATE IDAL PROBLEMS!!!

Re:Idle air control valve
 

i want to know more on the alternator effecting the IACV and idle

please let me know
jman

Re:Idle air control valve
 

shaved_civic is no longer with us.

Re:Idle air control valve
 

Hey got this off HT- might help:

http://www.geocities.com/playasrealm00/fcf956be.jpg

http://www.geocities.com/playasrealm00/fcf956bf.jpg
Bad Idle Troubleshooting

This is mostly for high and roaming idles but may work for low idles as well.

First, terms:

TB – Throttle Body
IM - Intake Manifold
IACV – Idle Air Control Valve (also called the Electronic Air Control Valve or EACV)
FITV – Fast Idle Thermo Valve
TPS – Throttle Position Sensor





I finally got the swap (b18a) in my civic but unfortunately when I started it up it idled at 3k then when it warmed up it had a hunting idle from 2k to 2500 rpm. I stood over that thing for 3 days, testing and scratching my head. On top of that I did a TON of searching on the h-t, hybrid boards, and on here. I hope what is contained within helps someone. Maybe they wont have to go through as much work as I did.

The idle on our Hondas is a tricky thing. It is controlled by two main sensors: the FITV and the IACV. The FITV is a mechanical valve that is controlled by coolant temperature (there is no ECU plug to it). When the coolant is cold the valve is open and letting air into the IM through a hole in the TB before the throttle plate. This essentially creates a small vacuum leak which in turn lets the motor idle higher than normal (supposed to be around 1500-2k for warming up). As the coolant warms up the valve closes and no longer lets air in through the hole in the throttle body. All the while the IACV, which is ECU controlled, is letting small amounts of air into the IM through another hole in the TB. Any amount of extra air the ECU is not expecting will confuse it and you will get either a high idle or a roaming/hunting/fluctuating idle. On to the troubleshooting.

First things first, don’t skip any of these steps. From what I have read (and experienced) usually small dumb things cause these problems so don’t overlook anything. Also refer back up to the pictures if need be.

1) Check your vacuum routing. On the underside of your hood there should be a vacuum diagram. If there isn’t a diagram under there, there is one in a Helms, Chiltons, or Haynes manual for your car (you should have one of these anyway). Remember, ANY extra air will confuse the ECU. Check for cracked or bad vacuum hoses. If in doubt just replace the hose, they are cheap.

The PCV valve could also be the culprit. Take it out and examine it. If it is cracked it could be causing a vacuum leak. Replace the peice if you arent completely sure it is ok (the helms/chiltons/haynes manuals tell you how to check it).

2) Check to see that your throttle plate is closed all the way. Take your intake off at the TB and check to see that nothing is blocking the plate. If nothing is in the way and it isn’t closed all the way, loosen your throttle cable.

3) Check to see if the nuts holding the TB and the IM on are tight, this was the source of my idle problem. If they are loose, tighten them.

4) Bleed your coolant. Some air bubbles may throw the FITV off and keep the valve open.

5) Take the 3 10mm bolts out of the FITV (you don’t have to take off the coolant lines). Then take off the 2 8mm bolts off the plate on the back of the FITV. Once the plate is off you will see a white plastic thing, screw that all the way in. This causes a TON of people’s hunting idle problems (it’s a source of a vacuum leak). Put the FITV back on and start the car up. If it still idles bad go on.

6) Clean the IACV screen(s). See Oz’s write up elsewhere on G2IC.

7) Make sure your car is completely warmed up. With it running, take the intake off the TB. There are 2 holes right in front of the throttle plate, these are the holes that feed the IACV (top hole) and the FITV (bottom hole). With your finger, cover up the bottom hole (it should NOT be sucking if your car is warmed up). If the idle goes down the FITV is to blame, either get a new one or take it apart and screw the valve completely closed (I have only read of people doing this, so I don’t know exactly how. Also, you will have to keep the engine speed up yourself when the car is cold).

Next cover both holes up with your fingers. The car should sputter and die (or almost die). If it does then the source of your crappy idle is the IACV. Replace it. If you want you can test the IACV. Shut the car off and put + battery voltage to the blk/yel terminal (on the valve) and momentarily touch ground to the blu/yel side. When doing this the valve should click, if it doesn’t, replace it.

If, when covering both holes the car still has a high idle, you have a vacuum leak somewhere. Again check the IM and TB nuts. You can spray carb cleaner around those areas and if any gets sucked in (the engine will rev) you have found your leak. Another source of vacuum leaks are where the FITV and IACV connect to the IM. Either replace the gaskets or use silicone gasket sealant.

8) If nothing has worked you should test your TPS. Probe the middle wire on the TPS plug (with the key on but not running, and the plug still connected to the sensor) with the + probe on the volt meter, and the neg probe to ground. You should have .5v with a fully closed throttle plate and 4.8v with it wide open. If the TPS is off, replace it. My TPS was .425v to 4.55v and it idles fine now so I don’t know how big the margin of error is. Also, it is pretty rare for these to go bad.

9) If, still, nothing has worked you might want to try a new ECU. This also is very unlikely, but worth a try.

10) If it still idles bad, go through the steps again.

I really really hope this helps someone out. It was a pain to have this mysterious problem and very little info on how to go about troubleshooting it. Comments or suggestions are welcome.

Re:Idle air control valve
 

That right there works like a charm! Thanks man.
I cut out a piece of sheetmetal,stuffed it in between and sealed it today.
All that i had to do is crank up the idle screw a little and it's all good now.

Added after a day of driving:
This'"trick" messes up the cold start,so it'll fire up and then die because the idle is no longer controlled.
However...this is in around freezing conditions and after a minute of driving it idles great.
Also fuel consumption went up..wich is a nice side effect for me personally since i don't have any fuelmanagement while boosting. ;D

Re:Idle air control valve
 

I have a ls vtec and i cant figure out why my cars idle is messed up. at times ill b cruising and when i come to a stop it sounds like it wants to die. for the most part it idles perfect then out of nowhere it will drop to like 250-300 then bounce back up. Anyone have any idea wat that is? wat should i do?

Re: Idle air control valve
 

I have a B16a2 engine in a 93 civic Si controlled with a P28 ecu! i have an idle problem to my idle is sturging from 500 to 900 i have tried all the things i have see in this post and nothing have work. I have unplug my negative wire from the battery so the car run only on the alternator and now the idle is ok when i replug the battery it restart idling bad! does this mean then my alternator is bad or something?

Re: Idle air control valve
 

The LS in my CRX does the other way around. When it's cold, the idle is real low, but when everything's all warmed up, the idle (if not adjusted) wil keep rising to like maybe 1500s. What can cause this. My TB gasket is new, BTW...

Re:Idle air control valve
 

i am having a problem like this and it is not a vacum leak. although it could be. Mine is caused by the FIV. which allows air to bypass the TB when cold and then it closes when warm. I am having a problem with surging and this is the problem even though i thought it was a vacumm leak or my IAC. so if you have a FIV check it along with a vacum leak and the IAC.

Re: Idle air control valve
 

i only hvae one hole in my throttle body and if i close it the crazy idol goes awaycan i just like jb weld a little plate where the eacv went and adjust tighten my throttle cable to open the plate? i know i have a small vac leak now because of my pcv valve allows all vaccume to come through and the hole on the valve cover sucks like crazy. should it do that?

Re: Idle air control valve
 

my car does the same ---- but its about 500- 2000 .. but i have my iacv blocked off and still have the y7 mani with ob1 havent gotten around to swappin the intake when the motors going soon. also i think my throttle linkage is all gummed up cuz when the idle stick high.. i just hit the pedal real quick and the idle sets back down to normal .. weird stuff

Re: Idle air control valve
 

my dohc zc sounds like it misses at idle, makes poping nosies during idle, replaced and cleand IACV, replaced and cleaned TB.

also if i lightly put my foot on the throttle, (just to open maybe a mm or so,) it sounds like its not getting enough fuel, runs rough till i press more, could that be the TPS?

Re: Idle air control valve
 

My car started doing the idle from 1k to 2k after I ran zdyne on it for 1 day. put the factory pm6 back in and still has the problems changed the idle air control valve with a used one but sprayed wd40 in there, after i installed it I didnt reset anything but i also had the screw under the TB turned up to idle it higher mayne i just gotta reset it, and turn all the specs back to factory. I'll let yall know how it works out.


Idle is solved it was the idle air control valve

Re: Idle air control valve
 

its not a vac leak...if you take the idle air valve off of the manifold you will see that its basically two ports for oil and air and than a big flat head screw on the top...usually that screw comes loose from vibration and the air vavle cant open all the way....so just take it off and tighten the ---- outa that screw and it will be fixed

done it many times

Re: Idle air control valve
 

My hyundai accent has a idle speed actuator. Ever since I boosted my idle was screwed! It would idle between 1200-2500 depending on how it felt and bounce around all the time. I just removed it , plugged the vacuum lines and left the acuator in place plugged in eletrically so I wouldnt have a cel. Then I used the screw on the TB to adjust my idle and its been fantastic. Idles EXACTLY as it should , never bounces around and improved my gas mileage greatly! All with no cel ;-)

Re:Idle air control valve
 

if you do this, what do you do about the coolant lines? still run them or no?

matt