OK I'm really lost, and the only reason I am posting and not headed to the dealership is because... well... I haven't had time (I'm at work as I speak).

Most people know about the IACV problems a lot of people have had or been having. OK well let me explain mine.

Car in case:
00 Civic D16Y8

Mods:
Injen intake, B&M FPR <-- only two things I think would make a difference Bosch platinum plugs, Autometer A/F gauge, AND 3 months PRIOR to the problem, I was running a Zex kit @ 55 shot.

OK history.

Intro:

I had no problems with idle prior to this, ran the Zex kit fine also, used from Sept. '01 - Nov. '01. Anyway, in January, while rolling to a stop (clutch in, or neutral) in rush hour traffic, my car's idle just rises to 1500rpm and sticks there. It would stay that way until I came to a COMPLETE stop. If I kept on rolling it would stay at 1500rpm. Gave no CEL or anything, so I just figured it was a fluke. Maybe the A/C or the fan turned on or something. I also disregarded it due to the fact that it wasn't consistent. It didn't happen at every stop and sometimes would go away when I turned the car off then back on again.


Part I:

Then sometime in March, it started happening more frequently. So I posted on H-T about what could cause it. Many said to check for vacuum leaks and to spray carb cleaner around the intake manifold, etc. Did all that. No change. A couple weeks after this, it threw a CEL. Checked the code. It was the code 14: Electronic Air Control. I was told that's the same as the IACV. When the CEL first came on, at idle, the rpms would bob fiercely from 2000-2200 back and forth. Made it hard to drive. The car would jerk violently (due to RPM fluctuations) at like 1/4 throttle and low rpms. I reset the ECU, the CEL went away as it should, but then it still would not idle normally, and now it would do the same thing a I said in the intro, but all the time, turning the car off then on again wouldn't help.

Part II:

Finally I decide I'm taking it back to the dealership (still under warranty) since I was due for an oil change as well. The idiots take the car, reset the ECU, and gave it back to me. I'm like ok. So I drive the car off, and it's still fluctuating. By the next day, the CEL is back. I make another appointment to get it checked out again. Leave the car there this time. This time they said they replaced the IACV and everything was fine... My ***. I get the car back, as I drive it off, the idle IS STILL fluctuating. I didn't get mad because I figured they replaced the IACV, and the CEL hadn't come on for almost a week. But then by the end of the week. It came back.

Part III:

Funny enough Honda was doing some customer serivce survey and so they called and I told them they didn't do a good job, etc. So they said they were gonna take it up with the head guy at the dealership, and they were gonna schedule me to come back again. They haven't called back as far as I know, and I have been busy with work, school, and Sundays the service dept. is closed. So. I'm PISSED. If started the car (warm or cold), let the car idle, it would just sit there seeking between 2k and 1k rpms for about 20 seconds until it settles at the normal idle. Driving it is fine. But occasionally the CEL would come on and it would do the same thing like I stated in Part I.

Part IV:

Same process kept on for almost a month (getting CEL, resetting CEL, getting pissed). So one day I decided to just forget about resetting and went home. Next day, with the CEL still on (remember I didn't bother reseting it), the car did the "seeking then setlle to normal " thing at idle all day, not like when the CEL first came on where it would go back and forth from 2000-2200. So I kept driving it around for the last week or so and it only did the seeking thing. Now, last night I'm at a light, and all of a sudden, the car begins acting like how it does when the CEL FIRST came on (2000-2200 rough idling). So I turn the car off, turn it back on. It kinda eases up. Drive around for a few more minutes, then it happens again. So I just turn it of... let it sit for 5 minutes at a friend's house. Drove home fine last night, drove to work this morning.


Present:

I was doing fine with it till last night. I was going to wait until I had time. But now I'm considering trying to borrow my dad's car this coming week and leaving it with the dealership with the instructions to just fix whatever it is and don't give it back to me till it idles right. But before that I also wanted to get the opinions of a few other people.

Could it be my fault:

Maybe it could be something that was MY fault. I'm going to try to get a stock FPR just to see if maybe that could be the cause (doubt it... I had that long before the problems started). Also someone was telling me that he experienced the same problem when he removed his Zex kit. He said that the tap on the TPS kinda tore up the wire and so it wasn't reading the correct voltage. So he cut it, and soldered the connection back together. I checked my TPS the wire doesn't look cut up, and also. I've removed the nitrous kit way before all this happened. Also, when installing my A/F gauge I had to tap a couple of wires before I realized which wire it was. One looks kinda hacked but it's not bad. But, once again... the problem started way before all this. I'm soooooo lost.


Things I've tried:

-Vacuum Leaks
-Carb cleaner
-TPS sensor (just the wire)
-Different ECU (tried a 00 B16A)
-New IACV (dealership replaced it)

Thing I haven't checked:

-Actual TPS sensor
-FPR

If you want to help me out, reply to this post, or email me or IM me at MemphBlak (AOL/AIM), CivicRyda2k (Yahoo), 6605258 (ICQ). Thanks.

Marc

 

My integra had a malfunctioning Fast Idle Thermo Valve that was giving me idle problems. If you have one it's under the throttle body. One way to check it is to remove the intake and look inside the throttle body opening. There should be two holes in the side of it. One goes to the IACV valve and one to the FIT valve. The one near the bottom of the TB is for the FIT valve. If when your engine is hot there is air being sucked in at the FIT valve hole, the valve is defective, replace it.

 

OK thanks... I'll check that out. But would that cause it to throw a CEL pointing to the Electronic Air Control/IACV?

 

You're right, it wouldn't set a code since the FIT is strictly a passive device. Try disconnecting the IACV and connecting it to 12V and ground, it should click. Try cleaning it maybe, although if it's brand new it shouldn't need it.

The voltages on your TPS are correct? (4.5 V at WOT and 0.5 V closed)

 

I'm sure the IACV works. I've disconnected it and the car kinda idles normal, then reconnected it then the idle flies up to 2k then starts seeking between 1-2k again then settles to normal. The TPS I'm not sure of. That I will have to check. Today when I get off work I'm gonna check that when I do the compression test.

 

top please help!!!

 

hey whats up civicryda....i'm having the same exact problem you are having. From the beginning to the end....I still have the problem and i have no idea on what to do. The IAC valve that i have....its' working and all of that but it still gives me code 14....same **** all the time.. i dont wanna reset my ecu everytime that goes on. its annoying reseting the radio and everything. i need help...can anyone help us?

 

yup saaaaaame exact thing... that's why i stopped reseting it. Reset it today though... VTC Civic and another friend told me to try that. That was at like 3pm. Since then, it came back on (at around 9pm). I dunno what to do. I just took some footage of how it idles tonite to show people.. maybe that might help.

 

i wish i could get some videos from my car doing that. I am clueless like you are....damn man why us huh? I've resetted mine yesterday and it hasnt come on yet but it will soon. I just know it....everytime i say it doesnt...it does. It pisses me off becuase i have stereo settings that i took a long time on and i have to reset it everytime that CEL light comes on.

 

true. thank God i still have the stock cd player. anywya.... what mods do u have done to ur car? maybe we can link it to something we've both done to our cars and try to isolate the problem.

 

OK... look all... I'm posting some vids of how my car idles. Peep them then tell me what u think.

this is a normal start up, well... not normal but when I say that I mean no CEL. The car was already warm. The only difference if the start is from cold is that it stays at around 1500 or 2000 rpm (can't remember which one) for a while:
http://www.tiora.net/~civicryda2k/Vi.../normstart.avi

taken right after rolling to a stop (the car idles at 1500 while rolling until COMPLETELY stopped... then it does what is shown in this video). then the motor is revved. Again, the car was already warm. Notice how it goes up normally when on the throttle, but when I come off, it drops quickly and drops low then jumps back up:
http://www.tiora.net/~civicryda2k/Vi...e/normrevv.avi

This is a video of how the car acts just as the CEL comes on (code 14: IACV):
http://www.tiora.net/~civicryda2k/Vi...initialcel.avi

This is how the car starts up from with the CEL on (after turning the car off then on again or just driving it with the CEL on for a while):
http://www.tiora.net/~civicryda2k/Vi...e/celstart.avi

sitting at idle, a short drive, then rolling to a stop. as u see the rpms drop and then jump back and stick to 1500... that's right when i put the car in neutral. In the end where it kinda goes down then settles is when the car is at a complete stop.
http://www.tiora.net/~civicryda2k/Vi...le/celroll.avi

That's it... hoping this helps someone find out what's the problem. Any problems with the links you can go to the vids directly here: http://www.tiora.net/~civicryda2k/

 

please... anyone?

 

OK, what happens when your engine is warm and you disconnect the IACV. The idle should drop but stabilize.

 

Also, it's a long shot but maybe the new IACV from the dealer was defective, or the ECU is toast. Try disconnecting the TPS and MAP to see if the idle stabilizes. You could try wiring in a dummy load ( a resistor, better yet a variable one, don't short it though) instead of the IACV and see if the CEL goes away. If it does then it's the IACV.

 

With the CEL already on... it just drops a little, then yes it stabilizes, and drives ok. If i remember correctly though, it kinda revvs and drops really quick. I can't remember now if it still does that idle thing or not though. Will try it on the way home from work today. I'm pretty sure it's something either with the IACV or, the wiring to it, or the vacuum lines connected to it... which are UNDER it so it's hard to check for leaks.

 

I DO think it might be a bad IACV from the dealer, or they just didn't change it. It LOOKS new though and it has some "inspected" stamp/label on it. But it was still idling weird when I left the dealer but I was so pissed of, plus I needed my car back so I didn't turn back to go curse them out. The ECU is not the problem, because I tried using my friend's B16A ecu and it still idled the same but I didn't have it long to see if the CEL came on. I'll try disconnecting both sensors today after work as well though.

 

ok checked my tps voltage just now... reads fine... i think... 0.52 to 4.58

 

top

 

top... come on people

 

top

 

top... anyone

 

I don't know alot about this stuff yet but I work on computers, chips can do some weird stuff when they dont get the right voltages, have u tested your battery?

 

Well... I doubt it's the battery cause that's the only thing messing up. But I will check it when i go home... although I think my friend did it just to make sure his voltmeter was working and i could sworn it read like 14 point something

 

If you've swapped ECU's and still get a CEL you know it's not that. If you've checked the ECU to IACV plug and wires for continuity (with an ohmmeter) you know it's not that. Only one other thing it could be. Does the IACV valve click when you put 12V across it? If not it's broken. Try going to radio shack, get a pack of assorted resistors, don't use less than 100 Ohms, start with say 500 ohms. Disconnect the IACV at the manifold. Wire a resistor across the plug terminals of the IACV, just ghetto rig it. Reset the ECU, and fire up the car. If you're CEL goes away you'll know it's the IACV. Most likely you're IACV is shorting to ground or has burned up.

 

1) Have swapped ECUs... dunno if that did away with the CEL or not.... because it doesn't come on consistently (ie... i reset the ecu today, the cel may not come back on for another couple of days) and I only had the ECU for a couple of minutes. However... the car DID still idle bad.

2) I haven't checked the ECU to IACV plug and wires for continuity with an OHM meter... but i know it's getting power because if you unplug the IACV plug the engine rpm drops... and when you plug it back in, it clicks (like a solenoid click). I'm thinking it COULD be a short or something though.

3) The IACV does click when I disconnected it then plug it back in (i'm guessing that's what u meant by running 12V across it)

4) I might try that resistor rig today also.

OK I think it's something to do with either incorrect/fluctuating voltage to the IACV (or possibly the TPS... which by the way... checked out at 0.52 at no thottle and 4.58 at WOT... this was done with the car off) OR something in the mechanical part of the IACV... I say this because the car doesn't give the CEL all the time... usually takes a day or so after resetting the ECU before it comes back on.