Bouncing Idle

[batever]

I had similar problems and it turned out to be clogged up coolant hoses that go to the iacv. I dont know if you looked into that yet

Actually a lot of my hoses were clogged.. Not just the ones that went to the iacv

I know that clogged brake booster lines were a problem in 3 cyl carbureted Geo Metros. I'm kind of wondering what the inside of my brake booster vacuum line is looking like now that I'm thinking of it.

[GeoffM]

haynes:

IAC system check

Idle speed is controlled by this system, which is actualted by the ECU according to running conditions of the engine (A/C, power steering, cold and warm running etc.)

CHECK

disconnect the elect. connector from IACV and measure the resistance of the IACV. it should be between 8 and 15 ohms. 13.7-13.8

check for continuity between each terminal of the IAC valve and ground. there should be NO continuity. If there is, replace. No/No

4. turn ignition to ON (not running) and measure voltage between the yellob/black (postiive) terminal and the black/blue (neg) terminal. There should be battery voltage. 12.99-12.56 Battery
11.9 IACV

5. If the voltage reading in (4) is not correct, have the electrical circuit for the iacv diagnosed by a dealer service dept or other qualified repair shop. NOTE: check the main relay for a possibel failure or a damaged connector.
Fantastic
ALSO:

FAst idle thermo valve. allows additional air to bYPASS THE ntake manifold to increase the idle speed. Once engine reaches operating temp, the valve closes, returnign the engine to normal idle.

1) start engine and allow to idle.
2) remove the FITV cover and place your finger over the valve seat. you should feel some airflow there. If there is none, replace the FITV.
3) If there IS airflow, warm up the engine and check again for airlfow. There should be none. If there is, replace.
Halfheartedly checked this, seemed to be fine.

ALSO
Starting Air Valve

11) using a hand held vacuum pump, apply vacuum to the starting air valve. and check that it holds vacuum. if it doesn't replace.

I have no reliable way to make a vacuum, so I couldn't do the last one. Is there any easy way to see if the main relay is going, other then pulling it?

[batever]

I have no reliable way to make a vacuum, so I couldn't do the last one.

Autozone will "lend" you a vacuum gauge and pump as part of their loaner tool program.

Is there any easy way to see if the main relay is going, other then pulling it?

not really/i don't know. , but the voltage test at the iacv should tell you something and help you decide whether to try to swap the relay out.. It's supposed to be battery voltage.

if you have a buddy with a cb7, ask him/her (I'm being very gender correct today for some reason--but the truth is don't think I know or have known a single woman who would let someone take parts out of their car to "test" with! LOL Most of them are very superstitious and protective of their car, it seems to represent safety etc etc to them) to let you use his main relay as a tester.


If you have a buddy around, I would probabnly have him/her check the voltmeter while you mess with the AC, power windows, etc, and see if and how the voltage changes at the IACV electrical connector/wire. You can also take a video of it with your iphone or whatever. If you have such devices. I would suggest duct taping teh digital camera /iphone into place so you don't drop in on the cement. or whatever.

[GeoffM]

Autozone will "lend" you a vacuum gauge and pump as part of their loaner tool program.



not really/i don't know. , but the voltage test at the iacv should tell you something and help you decide whether to try to swap the relay out.. It's supposed to be battery voltage.

if you have a buddy with a cb7, ask him/her (I'm being very gender correct today for some reason--but the truth is don't think I know or have known a single woman who would let someone take parts out of their car to "test" with! LOL Most of them are very superstitious and protective of their car, it seems to represent safety etc etc to them) to let you use his main relay as a tester.


If you have a buddy around, I would probabnly have him/her check the voltmeter while you mess with the AC, power windows, etc, and see if and how the voltage changes at the IACV electrical connector/wire. You can also take a video of it with your iphone or whatever. If you have such devices. I would suggest duct taping teh digital camera /iphone into place so you don't drop in on the cement. or whatever.

I might just end up buying a vacuum gauge after I fix this. The voltage drop will need to be fixed first though.
I know what you're saying about women and their cars. My mom has a habit lately of suggesting that my timing is off
I'll try to ask my buddy, but I doubt he'll let me. He's been constantly asking to borrow tools lately and I've been consistently telling him no.
I might just pull mine and resolder for the heck of it. I'll test voltages while I'm down there.

[GeoffM]

I'm thinking that if the problem IS the relay, this might be an issue:


I opened the relay. It looks wet, but it's not.


Anyway is there a way to test it, or should I just start soldering?

Also, check this out:


I plugged in my old one also and it made the noise too.

[batever]

So to be clear--it's making a humming noise (where is the noise coming from) when the IACV is plugged in, but not when it's not plugged in? when the key is in position 2 and the engine is not running?

I don't know about the relay question so i'll stand down on that one.

It's getting to the point that this is looking like a two way conversation between you and me, and I'm not experienced in this problem (though I am a patient diagnostician!).

You might want to open up this conversation on hondahookup.com (that's the first Accord site I ever was a member of--it's how I met deevergote and found out about cb7tuner.com) as well. TexasHonda there is very knowledgeable and experienced and might have some further pointers.

[GeoffM]

Both of my IACVs make a humming noise once I plug then in with the key at position 2. Definitely when the car is off. I can't tell when it's on.

That's one IACV on the car, and the other in my hand.

I resoldered the relay. I can't tell if it made a difference because the problem only happens with hot weather or stop and go traffic, I didn't have either today.

Also followed some Haynes troubleshooting. The voltage against ground for the top connector was something like .6, and the bottom was something like 14.

Can't remember the exact numbers, but if you added the top connector to the bottom one you got the battery voltage.

[batever]

I resoldered the relay. I can't tell if it made a difference because the problem only happens with hot weather or stop and go traffic, I didn't have either today.

If you don't want to wait for a hot day to see what happens, I would consider taking a hair dryer or a heat gun (on the low setting!) and heating up the main relay to say 100 deg F or 110 deg F (till it's warm to the touch) to see what happens. Take it slow and don't melt anything.


also, see my previous post that you already responded to, because I added something to it.

[GeoffM]

If you don't want to wait for a hot day to see what happens, I would consider taking a hair dryer or a heat gun (on the low setting!) and heating up the main relay to say 100 deg F or 110 deg F (till it's warm to the touch) to see what happens. Take it slow and don't melt anything.


also, see my previous post that you already responded to, because I added something to it.

I might try that. Everything is all put back together, but it would allow me to see the problem isolated.
I went on over there and made it:
http://www.hondahookup.com/forums/sh...58#post2286458

Also, one on one isn't bad. It gives me things to check for!

[GeoffM]

Looks like I'm going to have to take it to the dealership.
I'll report back with their findings.

[GeoffM]

Damnit

It was my throttle cable. It was too tight.

[reklipz]

Seriously, it was just that your throttle cable was too tight?

I'm having very similar issues as you: idle bounces between about 1k and 2k at times, usually when its hot outside and the engine is warm. I cleaned my IACV, measures about 13 ohms, and makes slight buzzing noise. I'm also having low rpm performance issues, and my throttle feels like its being held open for a bit when I let off the accelerator. I checked for vacuum leaks and couldn't find any. I think NY FICV is fine, engine idles cold at about 1.2k and then drops to 750 when warmed up.

I'm starting to suspect the air boost valve. However, I recently tightened my throttle cable, but it doesn't look like its too tight.

[Losiracer2]

Seriously, it was just that your throttle cable was too tight?

I'm having very similar issues as you: idle bounces between about 1k and 2k at times, usually when its hot outside and the engine is warm. I cleaned my IACV, measures about 13 ohms, and makes slight buzzing noise. I'm also having low rpm performance issues, and my throttle feels like its being held open for a bit when I let off the accelerator. I checked for vacuum leaks and couldn't find any. I think NY FICV is fine, engine idles cold at about 1.2k and then drops to 750 when warmed up.

I'm starting to suspect the air boost valve. However, I recently tightened my throttle cable, but it doesn't look like its too tight.

its most likely your IACV. I live in AZ where the temps get hot, one day, recently, it was over 115 and my car idled like crap. I couldn't get it to go below 1800 RPM, at times it drove itself when I shifted into 5th even when off the gas

I ended up lucking out and finding a brand new IACV at the JY on an H23 IM, I could tell by looking at it that it had very very low mileage, the internal parts were clean and white and I could see the spring mechanism crystal clear through the screen, plus the case of it was a clean matte silver compared to the rest of the manifold.

I threw that on and my car immediately idled rock solid at 750 RPM, no matter if I tapped the gas pedal abruptly, it immediately settled right at 750 and didn't surge down to 500 like my old one did sometimes.

So I really believe that a new IACV would solve that issue. A 20+ y/o electronic valve is a lot more tired and ragged than a fresh unit, no matter how much you clean it, the parts just wear out.

[Accord problems]

Today's updates:
I have no A/C.
The problem seems to occur only when the fans are on, or that's what it seems like.
No vacuum leaks, via starting fluid
IAC appears to work correctly, I cleaned it and the FITV.

New idle, I'm uploading a video. You'll see what I'm talking about.


Not as easy to hear it as I thought It'd be.

ive had this problem befor . your iacv is not set right . set right then you will be all good .

[reklipz]

So I really believe that a new IACV would solve that issue. A 20+ y/o electronic valve is a lot more tired and ragged than a fresh unit, no matter how much you clean it, the parts just wear out.

Thanks for the reply. Today I removed all of the vacuum lines for inspection and cleaning, including the firewall black box. All of the hoses "held pressure" when I plugged them with m finger and blew on them with my mouth, but a few had nicks in them so I replaced them anyway. I also replaced the O-rings on the air boost valve as I had some from an assortment kit that fit laying around. I drove to dinner in the heat around 5PM, and the "delayed throttle" issue was still present. The open loop 1k-2k rpm idle didn't occur, but that was a bit intermittent anyway, so I can't claim that's fixed. Next, around midnight I let my friend drive the car to show him the issues, and they were much less pronounced; perhaps gone. The car had cooled by then, and I drove it home and was unable to get the 1 second or so delayed throttle to show up. An hour later I drove home; the last half of my ride home was the smoothest I've ever felt the car while driving at 2k rpm. I should note that I had a couple of beers in me at this point (literally two; but I'm not a lightweight, so yeah...).

I'm going to be swapping the stock F22A1 TB/plenum/IM with an H22/H23 TB/plenum and an F22A6 IM+IAB+ECU sometime soon. Hopefully, if the problem isn't fixed, the new gaskets and seals from that work will fix the issue. If not, then I'll be looking for a different IACV.

I should note that lately I've been having code 41 (heated O2 sensor; overheated I think) being thrown when starting my car while it's hot outside. I changed my O2 sensor with a new Denso two days ago, and I have yet to see the code. Also, I reset the ECU each time I do work to try and fix the problem.

I'm wondering if perhaps the main relay is going bad? The EACV, O2 sensor heating element, and the injectors are all powered directly from the main relay. Is it possible that the heat (we're getting 100 F sometimes here in Nebraska), is causing the main relay to flake out at times, causing the O2 sensor heating element code, possible screwing with the EACV, and possibly screwing with the injectors causing the low rpm (sub 2k) performance issues I think I'm noticing?

ive had this problem befor . your iacv is not set right . set right then you will be all good .

FYI: Geoff has already resolved his issue, and he claims it was due to a tight throttle cable. More FYI: you're likely referring to the idle adjustment screw on the throttle body, as I'm pretty sure the EACV has not adjustable parts.

On a related note, while working on the vacuum lines, I readjusted my base idle. It was idling at about 850/900, but I figured it's worth a shot. I let the engine warm up, unplugged the EACV (the rpm dropped a bit at this point, which is expected of a working EACV), and adjusted the idle screw on the TB. With the idle screw all the way in, the rpm won't adjust to below about 650/700; I read that with the EACV disconnected you should be able to stall the engine via the idle screw, and if not it's an indication of a vacuum leak. I adjusted the idle as low as I could (650ish I think), and plugged the EACV back in; the rpm jumped back up to 800ish. I reset the ECU and that's where I left it to drive for the evening.

I'm going to the junk yard tomorrow: I'll try to snag some main relays, a new ABV and a new EACV. Time permitting, I'll also check the wiring, and check the EACV beyond a simple ohm test; I'll also check the ECU for proper EACV control.

This post is already long, so thanks a million (seriously) for sticking through to the end. Lastly: after doing the vacuum cleaning, I noticed that when I quickly open the throttle I hear a sound from near/under the air filter box. On my car (I don't know if this is with all F22A1s, or just my car), there is a vacuum line that runs from the throttle body all the way to a black box (similar to the one for the IABs on the F22A6 runners) past the air filter box. The air filter box has two plastic tubes, and one has a diaphragm on it. I assume that diaphragm is the one making the noise? I've never noticed it before, but it's possible it always has. When I place my hand on the end of the tube (I think it's the one with the diaphragm, I'll have to check), I can feel a quick rush of air coming out of it (when I quickly open the throttle).

Whew! That was a long one!