Won't idle when cold / auxiliary air valve / idle air control valve

Absolutely not a problem :)>:. BTW, just thought I'd mention that AC Idle-up diaphragm is one of the few parts you can purchase from Toyota that's cheaper than aftermarket off of rockauto. Last time I needed one I found it on ToyotaPartsDeal.com for $17.86 (I purchased 4 of them :)). Tim

wow this has been a great read for me. my poor van has been sitting for close to a year meaning I haven't used it much because I have a new job and don't use the van much. after reading the symtoms I believe my air vale is not working as it should. as usual Tim and the rest have help enormously with facts and pics.. thanx for that all. I spect I have a few bumping around in some Tupperware boxes and will replace it with one. I looked at what I thought will be an attack angle meaning I already have cut out a window in the firewall(hump) and should make this repair a bit easier. now just to be clear when I do start the van it runs just fine for maybe a minute then drops to idle then it just stumbles and rumbles and shakes after it does come to temp it runs kinda normal. think ill wait for a bit warmer weather and some extra time...did I mention its gonna snow here in Rhode Island this week! calendar says spring but I think thats a misprint

I feel compelled to say this isn't a job I would recommend doing until AFTER you've performed the tests (discussed earlier in this thread) and confirmed it has failed.........just saying :wnk:. Tim

o yeah I agree completely Tim. there still is much to learn before I go in and start tearing. the good thing is I'm not pressed to use the van much these days so I'm of the school slow and steady wins the race

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Originally Posted by timsrv

If the van warms-up and the heater blows hot air, then it's not related to the thermostat. It could be a failed air valve (between the intake manifold halves). When the coolant is cold, the air valve allows air flow (increases idle speed). When the coolant is hot, the air valve closes and prevents air flow (slower speed). To test, warm the van, then pinch an air tube going to or from the air valve. If the idle speed goes down, then you have a failed air valve. Tim

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Hey Tim,

Is there some trick to testing (or getting to a hose to pinch)? I pulled an idle air control valve off a junked van and brought it to my mechanic with the FSM, but he insists there isn't a way to access any attached hoses to pinch to find out if the one already in my van is faulty. Instead, he says he somehow tested the ohms on it and decided it was functioning properly. Is that possible? I don't know what else would cause my idle to increase as the van warms up. Unfortunately, neither does he.... Any thoughts?

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Originally Posted by isaiah44

Hey Tim,

Is there some trick to testing (or getting to a hose to pinch)? I pulled an idle air control valve off a junked van and brought it to my mechanic with the FSM, but he insists there isn't a way to access any attached hoses to pinch to find out if the one already in my van is faulty. Instead, he says he somehow tested the ohms on it and decided it was functioning properly. Is that possible? I don't know what else would cause my idle to increase as the van warms up. Unfortunately, neither does he.... Any thoughts?

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Please refer to post #48 in this thread.

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Originally Posted by timsrv

Please refer to post #16 in this thread.

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Thanks. Has anyone had this issue with their van - idle continues to rise as the engine heats up and doesn't ever return to normal - and had it be due to something other than a faulty idle air control valve? My 87 won't pass smog bc the idle won't stay in an acceptable range and my mechanic says it's not the IACV, but doesn't have any other suggestions. Up against a wall here, any help would be greatly appreciate. Thanks!

Hi all,

We are in process of getting our van registered in sunny California (originally from Manitoba, Canada) and we are being failed on our smog check because we had built our own replacement for the IACV when it failed years ago. The smog parts locator wants $180 for a "reconditioned" IACV, which seems ridiculous. The part number is 22230-73010.

We were wondering if anyone has a line on a 85 (or compatible) valve somewhere in the Bay Area or has an extra we could purchase.

Thanks!
Erik and Helena

Supposedly this part is NLA from Toyota.

Sometimes they pop-up on eBay. Otherwise might be a junkyard quest item.

< The smog parts locator wants $180 for a "reconditioned" IACV, which seems ridiculous.>
This might actually be a good deal if your van is your only vehicle and needs to be fixed asap.

Read this thread (if you haven't already):
https://www.toyotavantech.com/forum/...ight=air+valve

Good luck!

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Originally Posted by erik

Hi all,

We are in process of getting our van registered in sunny California (originally from Manitoba, Canada) and we are being failed on our smog check because we had built our own replacement for the IACV when it failed years ago. The smog parts locator wants $180 for a "reconditioned" IACV, which seems ridiculous. The part number is 22230-73010.

We were wondering if anyone has a line on a 85 (or compatible) valve somewhere in the Bay Area or has an extra we could purchase.

Thanks!
Erik and Helena

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Wow, These parts are pretty much extinct in the sense the IAC for the van is unique in that it is not shared with any other vehicle and so your best bet is scour the salvage yards assuming you can find any vans as they are now as rare as a hens tooth. Maybe eBay, although I just searched and found nothing. I would say if they sourced one for $180 grab it as its probably one the few left in the world because that is still less than what Toyota would charge if it was still available from Toyota.

Is the van idling high? if not, I am guessing it failed the visual inspection of the emissions test as a "missing component" and not that the Van was actually putting out higher emissions as a result of having a modified IAC? As long as you can set the idle at 850 or below that should be acceptable for passing emissions.

Hi all,

Thanks for the replies. Yes, we are well within the emissions output limits (better than average!) and are failing due to "modified emissions control components". To be honest, I think that the whole visual check thing is a bit ridiculous, if I'm not polluting what should it matter what parts I'm using.

Anyhow, after some calling around I found an 86 at a junkyard near my work. Does anyone have instructions for how to get to the IACV? It's been years since I removed the original one from our van and I didn't put my replacement back in the same spot. I seem to recall needing to remove the intake?

Thanks,
Erik

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Originally Posted by erik

Does anyone have instructions for how to get to the IACV? It's been years since I removed the original one from our van and I didn't put my replacement back in the same spot. I seem to recall needing to remove the intake?

Thanks,
Erik

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Again, read this thread. The reason I linked to it is because it has pics and advice on how to remove it.

https://www.toyotavantech.com/forum/...ight=air+valve

Looks like my air valve is not working. Did the hose test and the idle goes down when I pinch it off with pliers when hot. Looking at the picture that Tim supplied from the manual and knowing I really don't want to pull the intake manifold off again and I don't want to spend that kind of money I may have figured a way to solve the issue.

Since the air valve is stuck in its open state with or without the power connector on it means that it is functioning as if the engine is warm all the time. So wouldn't it be easier to add an additional air valve in series with the original by way of an external valve control? The only difference would be that it would move to both states very fast rather than opening the door gradualy inside the original by way of the heater.
To trigger it would be very easy. It calls for a certain time before it closes for warm running conditions. I am not sure what that is but I can find out for sure. Then we us a small micro controller as a timer using the same power connector the old one used.

Anyone see any holes in this solution? If this works we would all have a solution for it.

Here is one valve I looked at.

https://shop.advanceautoparts.com/p/...982%7CL3*15307

I also spotted another valve in the engine I could not identify. I have attach a photo. It sits just to the right of the partition between the engine and the air cleaner. In the pic you can see it is just south of the clamp screw that holds the big intake hose.

Anyone know what this is for? Squeezing one hose changes the idle so it must have something to do with that.


Thanks

MT

Looks like ISC VSV - IDLE Speed Controller. Excellent Thread titled 'What Does a particular VSV do?' listed as thread 1582. This thread has diagrams and several pages of discussion.

Cheers:wave1:

I know it's a long shot... But does anybody have an extra auxiliary air valve sitting around (22230-73011) they'd like to sell me for a good cause?! 😁

Quote:

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Originally Posted by timsrv

If the van warms-up and the heater blows hot air, then it's not related to the thermostat. It could be a failed air valve (between the intake manifold halves). When the coolant is cold, the air valve allows air flow (increases idle speed). When the coolant is hot, the air valve closes and prevents air flow (slower speed). To test, warm the van, then pinch an air tube going to or from the air valve. If the idle speed goes down, then you have a failed air valve. Tim

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Hi Tim, im trying to troubleshoot this part from my van also. I thought its opened and closed from an electrical signal, but what im getting from this (and the off vehicle testing method in the manual) is that its temperature sensitive and opens and closes based on the temperature of coolant flowing through it? Im a bit confused as to how it actually works. I “tested” my AA valve by hooking it up to a battery and nothing happened. When i was running the van last winter (never actually drove it) it idled low when cold and wanted to cut out, but seemed to get better as it warmed up. Any thoughts?
Thanks, James

As with many things in the FSM there is some information, but not enough to completely understand function. This leaves a little room for interpretation/speculation, which I'll leave to you. Here's what I know:

The auxiliary air valve opens when cold and closes when hot. There is a "shutter" or "gate" inside that allows or disallows flow. There is a spring constantly pulling on the shutter/gate trying to close it, but there is a bi-metal "stop" preventing closure. There is an electric coil (heater) wrapped around the bi-metal stop and when 12V DC is applied it heats the bi-metal stop as to promote movement towards the closed direction. There is also coolant flowing through the valve body and when the vehicle is warm (approx 180°F) this also promotes movement towards the closed direction.

Is the electric heater coil by itself enough to close the gate? FSM doesn't go there, so I don't know.

Is hot coolant passing through the body enough to close the gate without power to heater coil? I don't know that either :cnfsd:.

If either method were enough, why would there be 2 ways of heating the air valve? When I speculate, I have to assume both are required to achieve complete closure (but don't know for sure). The only tests shown in the manual are to check continuity of the electric coil. They say to check it warm (176° F) and you should see 40 - 60 ohms. They also say to start the van and watch RPMs while alternately obstructing/allowing air flow. When cold you should see RPM's drop when obstructed. If hot RPM's should remain constant. The manual also goes on to say the valve should be slightly open at room temp (68°F). Of course you cannot check that unless you pull the intake manifold.

As with any moving part, after 30 something years of service it's easy to understand how things could get gummed up and fail. If the valve is removed and at room temp (68°F), when you look through the bigger air passage holes, the shutter/gate should be slightly open. When putting an engine together, since this part is NLA, all you can do is check physical condition, continuity, and look through the hole (at room temp) to verify it's slightly open. If the shutter is slightly open stick a scribe in the hole and force the shutter to full open, then verify spring pressure closes it back to the same spot it was before. As long as the travel is free/consistent, and assuming it passes visual and continuity tests, then put it back into service. If it fails any of those tests, then start looking for another one that will pass. Tim

https://i8.photobucket.com/albums/a2...psxtbwmlod.jpg

https://i8.photobucket.com/albums/a2...ps5rknw7ak.jpg

Thanks for the response, Tim. Well written as always, haha. Looking at my air valve with the cover off, it appears the bimetal bar is warped towards the close position. The gate was slightly open at room temperature. I warmed it up with a hair dryer for a few minutes but didnt notice any movement. Maybe it just didn’t get hot enough. Next i might try throwing it in the refrigerator for a bit to see if it opens up. I tested the resistance and it was about 45 ohms at room temp. Im going to keep trying to figure this thing out, but if i cant then i might try rigging up a different kind of air valve from another toyota. Just a thought :)
Thanks! James

I tested my air valve when I had everything apart for the HG. IIRC, the valve still appeared partially closed when cold, but I was able to see it close by pouring boiling water through the coolant line.

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Originally Posted by llamavan

When you start the van, does it run rough and want to die (or actually die if not given gas)?

Gwen

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Reviving an old thread here -- the quote above are the symptoms my van is experiencing right upon startup, so I was curious if someone could expand on what causes this as it seems to have been brushed over in this thread.

For more info: on cold starts, the van typically starts fine (sometimes with a sporadic RPM, but nothing major and no odd noises/feelings from under the hood), but once the engine is warm it will stutter with large RPM drops acting like it's going to stall out, though usually doesn't, and/or it will stutter and stumble to it's start. It also tends to idle low when warm. Once driving I have no issues. I read through this thread and this one and this one, but am feeling a bit overwhelmed with all of the different valves and valve names and technicalities. I saw this thread which seems to be my same problem, but it had no information on it besides a possible FPR fix. Google tells me these symptoms are common to a faulty IACV (hence why I'm posting in this thread), but the info here seems to counteract that (also I'm not sure which one of the valves on our vans is the IACV :dizzy:).

Curious if anyone has had this same issue and successfully solved it? And/or could share some thoughts on what might be causing this? I recently cleaned my throttle body (which was very gunked up) as a first thought, yet the issue persists. It definitely seems to be an air-related issue to me, but I'm a newbie and could definitely be wrong.

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Originally Posted by llamavan

When you start the van, does it run rough and want to die (or actually die if not given gas)?

Gwen

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Hello, and thank you van gurus for this incredibly helpful thread. I’ve had ongoing cold start issues since I resurrected by 85 Van last year. I’ve narrowed it down to everything but this air valve. Cold start time switch is good (was replaced along with the Bosch connector), cold start injector passed ohm test and is confirmed to be working, I cleaned my throttle body when I did the TPS, I replaced all vacuum lines and verified there are no leaks, I even tried a spare ECU since I had one from the junkyard.

And still, when cold starting I got to put my foot on the throttle a little to get it to start. Otherwise, it’s exactly like Gwen describes here, I’ll hear it fire up but promptly die. I followed the on-vehicle check outlined on page FI-57 (that was quite a stretch with the longest pair of pliers I had) and it failed. No change in RPM.

So last night I pulled my intake and got the air valve out, and unfortunately it looks good, as illustrated in the repair manual??? Looks just like my other one, open just slightly at room temperature. Ohms are the same on both too, at 44.

I’m wondering if anyone knows a little more specifics about how these work. Like what’s the 7mm adjustment screw do? Does the heat coil change with coolant temp and then move the gate valve accordingly? If so then what is the actual electrical connector for? Or does it run off the ecu temp switch (which I have also replaced)? Lastly has anyone experimented with rebuilding these using parts from other Toyota air valves? I looked around online and it seems like other models had air valves just with different shapes.

I’m taking my fuel injectors to be cleaned and tested and I’m waiting on an intake gasket from rockauto, so I have a little while to figure out what I’m going to do. I would hate to put my new/old air valve in and have the same problem. Any input would be greatly appreciated, this forum has been a lifesaver.

So I'm having this issue when I start my 1991 Previa. It would die if I didn't give it gas when cold until I set the idle up higher to prevent that. It can go up or down a bit (±200rpm) as I'm driving if I'm in neutral at a stoplight after it's warmed up but it works fine for now.

I took off the throttle body and cleaned it up as it was pretty dirty (cat safe cleaner), as well as removed & cleaned the ISC (I tested it with 12v and it seemed to open/close fine) & put on new gaskets for both. The problem is still there. I have replaced the fuel filter in the past when I had the issue before but I believe it was only an issue at stop signs since it's a manual and not idling low on startup like it is now. That was only a few years ago and it's a messy affair so I'm hoping to avoid that. I'm going to do a cap/rotor/wires/plugs tune up soon to rule that out since it's been 60k miles. (I'm at 407k miles!)

On a side note, I did pull a bonehead maneuver (I know really stupid) and pulled out the MAF sensor (or VAF sensor) which yanked on the "serviceable" soldering connections about 2 months ago. It wouldn't start at all and found this video showing me to pull off the jumper wires and just solder the pins straight to the board and it worked! I'm assuming that it has nothing to do with this issue as it ran fine for at least a month and a half before this issue popped up. This guy saved me a long drive to the junk yard. https://www.youtube.com/watch?v=CXCpYj-r_lI&t=714s