travie_vtec

I drive a 1999 Honda Civic EX Automatic. Y8 head on a d15b bottom.

The other day I got a CEL. It came up as P0505 "idle air control".

So I read up on things and read that you sometimes have to clean them.

Since 9am today, I have been cleaning this thing. I used 3 cans of carb cleaned and a toothbrush to get rid of as much junk as possible. When I finished, I put everything back together, and took it for a drive.

No CEL. Driving was nice, except I put it in neutral while moving, and the idle goes up and down. So I came back home and parked it. Idle was up and down for a little, but then was steady. Took it for another drive. Stopped at a stop sign and sat for 2 mins (when stopped my CEL used to come on for P0505) and still no CEL, and no funky idle. Got moving again, put it in neutral... funky idle came back.

Went home and sat in neutral this time. Idle bounced for a few seconds and then went steady.


I'm so confused. Maybe I need a new IACV?

Whats your input guys?

rick_rabies

iacv can be had at the junk yards. but alot of things can effect idle. while sourching out another iacv. check your ficv...if you have one. also. coolant? leak? compression? transmission good?

travie_vtec

Coolant is full, no leaks. Transmission is good, it shifts great.

clkupai

try checking for vacuum leaks. mine had a similar issue and i tried everything until i found out there was a small leak on the throttle body.


Posted from Honda-tech.com App for Android

speedjunkie_g35

Did you get all moisture out or let it dry really good? For some reason when I first cleaned mine, i didnt let it dry all the way before putting back together and it didn't cure my idle. Second time month and half later, there was still moisture in it. I used my compressor to blow everything out really good and it purs like a kitten now.

travie_vtec

i got a new one coming for $80. If that dont fix it, i'll change all the hoses and gaskets again

H0nda_Crazy

I have the same issue.
The idle will bounce when in park or neutral. Put it in drive and it goes away.

I cleaned the iacv so I'm guessing and hoping that replacing the fiv will fix it. I don't hear or see any vacuum leaks.

travie_vtec

do auto civics have both iacv and fiv? if so, weres the fiv?

Former User

The Y8 engine does not have an FITV.

Try bleeding the cooling system --->

Bleeding the cooling system may take 20-30 minutes.

1) Park the car on an inclined driveway with the front end higher than the rear.

2) Push the dash heater lever/**** to MAX heat.

3) Follow the directions in the diagram below (hint: the bleed bolt is located where the upper radiator hose connects to the engine):

travie_vtec

Y8's dont have a bleeder bolt do they?

Former User

You have a hybrid engine. I believe the D15b block would have the bleeder bolt.

travie_vtec

wasnt there

Former User

That's fine. Do this...

Bleeding the cooling system may take 20-30 minutes.

1) Park the car on an inclined driveway with the front end higher than the rear.

2) Push/turn the dash heater lever/**** to MAX heat. Fan need not be on.

3) Follow the directions in the diagram below

travie_vtec

gunna do this once my engine cools down some.

Just replaced the IACV, and the gaskets, and theres no change.

speedjunkie_g35

My dizzy was causing some idle issues not to long ago. Might want to look into that

travie_vtec

vacuum leak -_-

i leaned into my engine to look at something, and I felt my finger being sucked in

travie_vtec

Fixed this... for about a week, now new issues.

1. When I plug my obd2 sensor in, I still get a p0505, even if I dont have a CEL.

2. If i let it warm up in park/neutral, I will get a CEL, only after a bit of time.

3. Tonight I went for a short drive, and while in motion, put the car in neutral, the cars idle bobbed up and down some, then went normal. returned home, sat in driveway in park, got a p0505.

4. Then when I went home, my car was whistling... almost sounded like a firework. I thought maybe it was my speakers, but it was definitely coming from the car. I parked and popped my hood, and couldnt find a hose that came off. Drove the rest of the way and didnt hear it.

Saturday my mechanic is gunna look at my car, but it i can fix it before I gotta pay, i will.

Former User

Sounds like a vacuum or intake air leak.

travie_vtec

I covered the Throttle Body, and the car stalled, so I'm guessing that rules of a leak.

I ordered a new PCV and some vac hoses.


I thought I fixed it. Changed the IACV. Found a vacuum leak. Capped everything off. Got rid of a cracked vacuum tank that had no purpose. Burped the coolant like 5 times and never saw bubbles.

I still get an idle that slowly goes from 1000 to 1500 and then after a minute of two, drops to 8-900, then gives me a CEL, and boom constant ~1500 rpms.

I have searched and searched, and there hasnt been any real answers that i've found.

Am I missing a vacuum hose? i know theres a hose that goes down through the intake mani, but I can't seem to find where it goes.

After I fix it, im getting an Integra.

Car is a 1999 Honda Civic EX with a "D15Y8" and is automatic

HondaPartsHero

Can you take a picture of the IACV you replaced?

travie_vtec

I dont think the IACV was even the problem.





Took the sensor part off to clean around the magnet.

Other then that its a clean IACV... so i spent $80 on a new one for no reason.

travie_vtec

Update!

So I ordered 2 sets of hoses from Honda. Thick and thin ones. Replaced all hoses going to and from the IM and any other air part.

As stated before, IACV was replaced. I do not have a FITV.

I've burped the coolant many times, just to be sure.

put my hand over the TB inlet.. stalls engine.

Car ran decent, even with the idle screw all the way down.

I was stuck waiting for a train to pass.My idle was going up and down from 1500 to 1200 , and the yellow light from hell appeared.

Cleaned the code... P0505 of course.

the idle wouldnt surge... the car just bogged when I was a low rpms or moving from a stop.

Now I think im going down a checklist. Next for me is to change the TPS and the ECT sensors.

If that doesnt work, IM gasket. If that dont work... swap head.

I would also like to thank everyone who has put in some for of input. Every idea gets me 1 step closer and being able to finally enjoy my car.

Soundbyte037

This is a crazy thought but it happens, Could you have accidently mixed up the plugs that connect to the IACV and TPS. They are the same sized plug and will cause a rough idle if not plugged into the correct connectors.

AnErin

Heh, us new-edge cougar owners know ALL ABOUT IACV problems. It is part of our initiation.

When you did the IACV, you didn't forget to replace the gasket or anything? And as said - mising up the hoses can cause weird problems.

With just throwing parts at it, it would probably be cheaper to have a shop diagnose it, and then if possible, do the work yourself.

travie_vtec

i guess i never checked to see if the coolant lines were put back in the right spots... but it doesnt seem like that would cause any problem, since all it does is a loop.