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Thread: What does a particular VSV do? See excellent attached diagram.

  1. #41
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    Re: What does a particular VSV do? See excellent attached diagram.

    Quote Originally Posted by markhmcb View Post
    Tim, how does one go about adjusting the earlier one with the adjustment screw? My 1989 2wd LE has one.

    Thanks,

    Mark
    The "Idle-up" diaphragm's job is to increase idle speed to compensate for loads that would cause the engine to stall or stumble. A properly adjusted one will simply aid the engine in maintaining the correct idle speed when these loads are present.

    With the AC off, set your idle RPM using the idle screw adjustment on the throttle body. Then turn on your AC, wait for RPM's to stabilize, then set the idle speed again (to the same spot as before) using the adjustment screw on the "Idle-up" diaphragm. Tim

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    Re: What does a particular VSV do? See excellent attached diagram.

    Here's a question.... where are you guys getting these amazing diagrams? Are they downloadable somewhere?
    Man, I'm hoping they're not somewhere obvious. ;)

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    Re: What does a particular VSV do? See excellent attached diagram.

    This is a great thread. I've got a problem that I haven't been able to troubleshoot yet and am hoping someone may be able to point me in the right direction:

    '88 4wd w/ AC (AC is non-functional and condenser has been removed)
    I'm having a high idle issue - around 1200rpm when warm. This has been going on for months but didn't realize how high it was until I installed a tach.

    When first started and cold, it idles around 600-800 until it warms up and then goes to 1200. I also am having a cold start issue (which may or may not be related where it feels like it needs to build fuel pressure for the first start of the day - and completely goes away after the van warms up).

    My thought is a vacuum line may be installed backwards? Which would make it idle low when cold and warm when hot? Is that even possible?

    Or maybe a valve is stuck open or closed?

    I've replaced the following:
    - Cold start valve
    - Idle up diaphram
    - Bimetal VSV
    - TPS

    Also within the last 100 miles recently:
    - Plugs
    - Cap
    - Rotor
    - Wires

    Would greatly appreciate any additional direction - and thank you!

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    Re: What does a particular VSV do? See excellent attached diagram.

    This is EXACTLY how my '88 4WD runs. Same cold start RPMs and warm RPMs as you.

    I'm almost certain that it's the air valve causing the issue. Unfortunately, it's so hard to find an air valve these days, and the job to replace it is difficult enough that I don't know if it's worth it for me to pursue fixing it.

    I'm considering adjusting my warm idle down to acceptable RPMs, and just getting used to using the gas pedal after cold starts for a couple mins.

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    Re: What does a particular VSV do? See excellent attached diagram.

    Yeah the air valve is on my possible list of why it is happening - but am hoping it is something else.

    I have adjusted my idle down on the throttle body pretty much all I can, and it still is around 1200 RPM at idle. I have a California smog test coming up in the next few months and won't pass with that high of an idle... Did you have another means for lowering it?

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    Re: What does a particular VSV do? See excellent attached diagram.

    I don't know how thorough your Cali smog inspections are but when I still had to smog mine in Wa state I had idle issues. I eventually determined mine to be a bad tps. Prior to that when I would get a smog test I would turn on the rear heater fan while they weren't paying attention. It brought the idle just under there 1100 rpm maximum and got me through the test. Obviously the best solution is to troubleshoot and repair but if you need to pass an inspection in the meantime so you can keep driving it this trick may be worth a shot.

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    Re: What does a particular VSV do? See excellent attached diagram.

    So I adjusted this guy on my 1984 TV

    Name:  IMG_6732.jpg
Views: 1229
Size:  93.3 KB

    But I opened it as far as it would go, if I went further it sounded like air was coming out.

    I turned the van on and listened to the normal idle without any electronic loads on the battery and then I turned the AC on and let it idle for a bit before I just the plastic screw.

    But it still doesn't seem to be idling high enough to keep the battery from dying with AC on.

    It definitely kept it from dying as fast as it was before but it slowly starting creeping down into the low 13v range.

    Anything else I can do or maybe I did something wrong?

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    Re: What does a particular VSV do? See excellent attached diagram.

    I seriously doubt it's low voltage causing it to die........that takes place somewhere around 10 volts. If your battery is strong enough to restart after it dies then you can rule out the charging system. Sounds to me more like you have a vacuum leak. A vacuum leak will cause the van to run rough AND can prevent the idle-up VSV/Diaphragm from operating as designed. Carefully check all vacuum lines and if you have a vacuum gauge, take a vacuum reading at idle and report the results. Tim

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    Re: What does a particular VSV do? See excellent attached diagram.

    And check the intake tube for cracks!

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    Re: What does a particular VSV do? See excellent attached diagram.

    For what it is worth, I pulled 2 Auxiliary Air Valves from junkyard vans yesterday.

    1 from an 86 and 1 from an 87. Both were part #22230-73011 and not #22230-73010 which I had expected. Mostly putting this out there to say that those part numbers are likely interchangeable.

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    Re: What does a particular VSV do? See excellent attached diagram.

    Would the AC Idle Up VSV cause high idle issues if it was bad? Enough to keep the idle up at 1200rpm?

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    Re: What does a particular VSV do? See excellent attached diagram.

    Quote Originally Posted by Gambit View Post
    For what it is worth, I pulled 2 Auxiliary Air Valves from junkyard vans yesterday.

    1 from an 86 and 1 from an 87. Both were part #22230-73011 and not #22230-73010 which I had expected. Mostly putting this out there to say that those part numbers are likely interchangeable.

    Can you post post an actual photo of the part and where is it located?

    Thank you

    JDM

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    Re: What does a particular VSV do? See excellent attached diagram.

    Another auxiliary air valve question - At what temperature roughly does this close? Does the thermostat need to be open to reach this temperature controlled switch?

    Thanks

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    Re: What does a particular VSV do? See excellent attached diagram.

    The auxiliary air valve is supposed to be fully open when coolant is @ or below 68°F. It's supposed to be fully closed @ or above 176°F. It's on the heater hose circuit which bypasses the engine T-stat (it gets flow regardless of engine T-stat position). Tim

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    Re: What does a particular VSV do? See excellent attached diagram.

    Some of this comes from the “what is this/part number” thread. Posts 259 and 260.


    From Member AD2101:

    Tim,

    Any idea if there is a functional difference between Idle-up VSV
    90910-12003 vs 90910-12005? I searched ToyoDIY and it appears it has the same application just a different last digit.



    TimÂ’s response:

    Not sure. It's very possible, even likely there are multiple VSV's used by Toyota (and others) with the exact same function. I'm guessing the only difference between some may be the configuration of the mounting bracket. If you find one that you think may work, you can test to see if it's functionally identical. Just try blowing through the nipples to see if air flows (normally open) or if it does not flow (normally closed), then activate it with 12V and blow again. Once you know how it functions you can test other similar type VSV's found elsewhere (even on other makes and models of cars). If/when you find one that functions the same way you could use that. If it doesn't mount the same you could wire tie it up or just let it dangle from the wires/vacuum hoses. Tim



    Per tims suggestion I tested my idle up vsv (with the broken nipple). This vsv appears to be normally closed. Unfortunately, the 90910-12003 I got from a junkyard did not work with TimÂ’s 12v test. No air passed when hooked up to 12v. Same was the case for 90910-12005. Appeared to be normally closed, hooked it up to 12v no air blew through.

    At this point wether 90910-12005 will work, looks likely but still inconclusive. However, I did learn 90910-12003 is normally closed.

    If im pulling my air conditioning, would there be a way to “loop” the vacuum so I didn’t need this VSV and my idle would return to normal?

    If not, anyone with an idle up vsv, IÂ’m on the hunt. Willing to buy. I pay promptly.

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    Re: What does a particular VSV do? See excellent attached diagram.

    To keep it simple I only mentioned the most common VSV's functions. There are also other more complicated ones. Some have more than 2 nipples and some will perform multiple functions. Another common function is to vent/seal depending on their intended purpose. If you see one with a round cylinder thing on one side, chances are it's meant to vent to atmosphere. Like the pressure-up VSV, when it's activated it will close the vacuum side while opening the fuel pressure regulator side and venting the FPR to atmosphere. All I'm saying is that when you are testing these it's important to understand intended function. If you don't know, then be sure to blow in both sides while testing. If nothing else it may help you understand function better. Tim

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    Re: What does a particular VSV do? See excellent attached diagram.

    Gotcha, thanks Tim.

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    Re: What does a particular VSV do? See excellent attached diagram.

    Anyway to know if the idle-up diaphragm is bad? My AC idle-up VSV seems to be working; it lets air through when provided power–but nothing happens when I adjust the nylon screw on the diaphragm. I also just redid all of my vacuum hosing, hoping that would help, but when I throw the AC on I lose ~250rpm, from 750 to 500. The car still cycles through idle increase momentarily while the AC is on, kicking it up to about 800rpm, but then drops back down to 500. My understanding is the AC idle-up VSV should kick the rpms back up to 750, should it not?

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    Re: What does a particular VSV do? See excellent attached diagram.

    So I got my OEM idle-up diaphragm from the dealership, threw it in and, unlike the old one, when I adjust the nylon screw it effects the idle speed. Now, following Tim’s advice on setting idle speed and the diaphragm, I set the idle speed with the screw on the throttle, put the AC on, then adjusted the diaphragm to match the speed. The only issue is that when I turn the AC off, the diaphragm still seems to be activated and kicks the rpms up. So, it would seem as though my idle-up is always being engaged. My idle-up VSV seems to be functioning properly, so does that just leave the air control valve on the power steering as my only culprit? Could it be stuck open?

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    Re: What does a particular VSV do? See excellent attached diagram.

    Welp, I went back at it, and after perusing an AC thread, I decided to undo the grounding of my coolant temp switch, and voila! My idle-up diaphragm only kicks in when I’ve got my AC on . Seems like grounding the CTS caused the idle-up diaphragm to always be active.

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