Because this seems to be a common problem with civics, especially EK's and EM1's.
I didnt realize it happened so much until it happened to me, an only then i noticed the ridiclous amount of posts like 'idle acting up, IACv, etc'


First off, the code you're getting (P0505) same as CEL 14, is not IACv like how it says in the FAQ's stickied in here, Club Si, etc...
P0505/Code 14 is <U>Idle Control SYSTEM malfunction</U>, not IACv.

Possible Causes:

-IACvalve mechanical malfunction
-Throttle body clogged port, improper adjustment
-Intake manifold gasket leakage
-Intake airhose loose leakage
-Vacuum leak
-ECT sensor incorrect output
-Throttle Posistion Sensor incorrect output
(for the TPS incorrect output, this might be only for motors made in '96)

Try an check these things.

Start the motor, hold rpms at 3000 until the radiator fan comes on, then let it idle.
Check TPS, with the throttle fully closed, the TPS should be around 10%
(coolant temp should be around 200 degrees, give or take 5 degress or so.)

if your idle is above 550, check for vacuum leaks. Take the intake off, put your finger over the lower port in the throttle body. if the idle doesnt drop, check for vacuum leaks, make sure the throttle valve is closed completely.
if the idle does drop, adjust the idle speed. if you cannot adjust, replace IACv.

if the idle is less than 550, do the following:
disconnect the connector from the IACv.
(for A/T, d167y) if the engine speed doesnt increase, replace IACv. if it dies increase, adjust the (base) idle speed, clean the ports in the throttle body as necessary.

(for B16A2, d16y5,y8)if the engine speed drops or stalls, adjust the (base) idle speed, clean the ports in the throttle body as necessary. if the engine speed doesnt drop, or doesnt stall, replace IACv.

Do these before you decide to go down to Honda and spend $290 on a new IAVc and you dont need it. But if you do, i have one, brand new in box that i cant return, so its for sale.

Modified by i. at 4:11 PM 10/16/2007


Modified by i. at 4:13 PM 10/16/2007


Modified by i. at 7:19 PM 10/16/2007


Modified by i. at 7:22 PM 10/16/2007

 

bump

thanks

but mines not throwing a code and it works fine after i bump start the car

 

How much for the IACV, and will it work with an 01 Civic SI?

 

i dont think it would work on an 01 civic.

 

Would the Ports for the IACV being dirty cause it to not work on occasion?

 

Yeah I noticed mine (EK9) goes down in the 100s as well... Usually around 500 or so. After I revv it a few times it goes back to 1000, and sometimes when I start it it goes up to 1500, but I think that's only because it's cold outside.

 

Can I just clean the IACv on our '99 Civc EX sedan D16Y8 in 5-speed the car has 110k. I don't want it to get gunked-up and start misbehaving. Should I just use TB cleaner on it, like the Throdle Body?? Anyone have any pics of the IACv on these cars?


Modified by shortlid at 7:14 PM 11/13/2007

 

Again can I just clean the Idle Air Control Valve.

 

what do you mean by adjust the (base) idle speed,

 

thats just the way the service manual is written. base idle, is simply idle in layman's terms. should be around 750 for a b16, b18 too i think.

 

i think the idle is fine it just surges up and down i dont no why when i un pluged IACv the idlw went way down so im thinking thats good

 

Well I cleaned it out with Throdle body cleaner and it no longer does the surge up and down thing. Was cloged with carbon build-up. You shoudl clean yours out to fix it as well.

 

i cleaned mine twice now and it still dose it ... ill do it a 3rd time 2maro anything els

 

I kinda have a wierd story/problem with my iacv sensor.. Ne ways its on a jdm b18c-r if that helps. I was driving with a bad Iacv sensor for a while.. (high idle, surge after warm up) but no CEL. After I replaced it with another one (off a used car) Runs perfect idles/runs fine, but now I have a CEL code 14.. kinda wired..

 

i unpluged the iacv sensor and the idle seemed to stay the same but then when i pluged it back it the check engin light came on and the idle was bounceing really fast and i got the code again po505

 

Sounds like you IACV could be bad then!

 

could someone tell me if mines is bad i unplugged it and the idle raised??? then once i reconnected it , it went back to its surge

 

i got that code a while back, i just replaced the iacv and it was fine after that

 

i soaked e IACv with gum cutter for about an hour put it back on but left it unpluged change the idle to about 700 with it unpluged then i pluged it beck in and its been 2 days now and no code or surging idle

 

Yes, a good soaking will fix a REAL gummed up IACV right-up. Glad it worked!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shortlid &raquo;</TD></TR><TR><TD CLASS="quote">Yes, a good soaking will fix a REAL gummed up IACV right-up. Glad it worked! </TD></TR></TABLE>

I only sprayed carb cleaner every couple of minutes didn't work. I will try to soak it tomorrow, thnxs

 

I'm a noobie at this car stuff.
Got my 1st car...
'94 Vtec Civic Ex coupe 5speed.
The idling isn't steady.
It bounces from 1500-1750 rpms.

Got a p06 ecu which from what I've read is for a '92-'93 Civic/DelSol.
Will that ecu be ok? Or should I look for a p28 regardless?
Or any other ideas.
Keep in mind...car is still needing to get registered and then inspected.

Hmmm...
Also there 2 wires sticking out that seemed to have been cut off.
Not sure if it has to do with the IACV or whatnot.
I am typing this on my phone therefore I won't be able to upload a pick of it or my rpm gauge.

Please if you can help. Email me at rawrz@tmail.com for it.
If possible upload it for others to see and post there opinions.

Thank you.

 

I got a question with mines.
My Code 14 shows up and starts to bogg and lagg and my idle goes at 1500 up and down but not much but enough to make my car run like **** but things is Once i take out the battery and reset the ECU, everything runs fine after that. Sorry, I'm not so well at explaining things.

 

i got a ? when my iacs plugged in i dnt get a code but the idle jumps from 11-1600. when its unplugged it idles around 600 steady but stutters between 1500 nd 2000

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by OP &raquo;</TD></TR><TR><TD CLASS="quote">if your idle is above 550, check for vacuum leaks. Take the intake off, put your finger over the lower port in the throttle body. if the idle doesnt drop, check for vacuum leaks, make sure the throttle valve is closed completely.
if the idle does drop, adjust the idle speed. if you cannot adjust, replace IACv.</TD></TR></TABLE>

Correct me if I am wrong, but isnt the lower port for the FITV? Shouldnt that be closed if the engine is warm? so should the vacuum change when plugging the lower port?

I pulled both the FITV and IACV off last night and cleaned them. Now I get the code every time I drive. I am going to check to see if I have any new vacuum leaks after work, those o-rings and seals were pretty old and I didnt have anything to replace them with.