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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: 66
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 68F. It's supposed to be fully closed @ or above 176F. 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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