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I get tired of dealers wanting to sell new parts rather than cleaning/fixing the parts that are already present.
Has anyone ever effectively cleaned their idle-up actuator/diaphragm? If so, I'd like to hear about your experience, as I plan to clean mine this weekend. Since it includes a diaphragm, I guess it would be better to use something like a mass air flow sensor cleaner rather than a throttle body cleaner.
I'd also like for us to share measurements that Toyota doesn't feel it necessary to provide. It's much easier to diagnose a part when we know exactly how it is to act. For instance... my idle-up VSV vacuum; what is the range of acceptable vacuum for that switch. This is what mine measures:
Intake A/C off = 18"
Intake A/C on = 14"
Exit A/C off = 0"
Exit A/C on = 5"
When I connect my intake to my exit vacuum, bypassing the VSV, my idle up actuator/diaphragm increases my idle, but 5" of vacuum isn't enough to do so. I found a replacement on EBay, but that dropped the reading from 5" to 4". It would be nice to know if this is within a normal range, so I can determine if I received a defective part or not. The part I replaced is no longer manufactured, but it is part #184600-0510. I understand the replacement parts for the VSV and idle-up diaphragm on my '94 22-RE are: 88606-35020 is the diaphragm and the valve is 88690-89132.
I'd appreciate if people would share their vacuum measurements, along with any cleaning tips you've discovered have worked.
I removed and cleaned the idle-up actuator. There was a little carbon on the top side, but nothing that would reduce the vacuum. The bottom was clean. The results didn't change much, other than the intake with the A/C on is now 15". I am idling at 1000RPM with my A/C off and 600-700RPM with my A/C on. Adjusting the screw on the actuator still does nothing. I wouldn't say this is a significant problem, but I am curious as to what is happening. Since I replaced the VSV, and got the same results, I am sensing there may be a problem with the idle-up actuator/diaphragm. I'd truly appreciate some feedback on this issue. Does anyone have any ideas what is happening? Has anyone ever experienced this issue and actually solved the problem?
Was this issue ever resolved? I have the same issue with 94 22re truck. I suspect the diaphragm is not functioning as it gets vacuum from the vsv when the a/c kicks on but engine does not idle up. Should idle up from 750 to about 1000 rpm. Has anyone torn apart one of these actuator diaphragms to see how they are constructed inside and what it is that actually fails? The part is discontinued and having a really difficult time locating another one, even in the salvage yard. Ebay sellers that do have them are selling for way more than what the part used to be available for new from dealer. No guarantee that these Ebay parts work as nobody seems to know how to test them. Help.
BUT: idle-ups (AC and PS) work by injecting atmospheric air into the intake manifold (increased air flow=higher rpm). So step 1 should be to pull the vacuum line from the manifold, and see if the idle goes up the amount you want. If nothing happens, then the input to the manifold is blocked.
I don't know much about the 22re, but the 3VZE has an issue with "gunk" buildup in the plenum (mostly from the PCV system). This can block any of the vacuum ports, including those for idle-up.
Thanks Scope103 for the link. I have that same test procedure in my Haynes Repair Manual (Chapter 4-11) and had performed it already. That procedure is for the vacuum switching valve. Mine checks out ok. I have two spares that I picked up. They test good too and I have installed them on my truck. No idle up still. There is a diagram in the link for the idle-up actuator also but no test procedure for it. Only a test procedure for the VSV.
Regarding pulling the vacuum line from the manifold, could you point me to which line you are referring to. There is a large line that comes off the throttle body and goes to idle-up actuator. Then there is a line that runs from the air intake chamber to a port on an air control valve on the power steering pump. There a second line from that air control valve back to the idle up actuator. Then there are the two smaller vacuum lines that connect the VSV to the idle up actuator. I can try to post a picture. Interestingly enough, if I disconnect the two small vacuum lines from the VSV and then connect them together, the idle goes up. Everything that 4Xtruck explained in his 2011 post is exactly what is happening with my truck. There does not seem to be a lot of vacuum that comes from the VSV when its activated. It just seems to be designed that way. All three of the mine perform the same way.
Last edited by twotwore; 04-26-2017 at 03:06 PM.
Reason: typo
On the 3VZE, the A/C idle up VSV connects to the intake through a rubber vacuum line. On the 22re, the VSV apparently bolts to the intake manifold with a hard line. http://web.archive.org/web/201102052...24vacuumsw.pdf (Like I said, I don't know much about the 22re.)
To test whether the VSV CAN do anything, you want to connect the intake to atmospheric air INSTEAD of the VSV. So I guess you just temporarily remove the VSV from the intake on the 22re. Then with the engine running, you can put your thumb on or off the hole to see if the idle changes.
Make sure you don't confuse the A/C idle up (through a VSV) and the PS idle-up (a valve on the back of the PS pump).
this is the a/c idle up vsv and the p/s idle up on my 22re. the a/c uses both, i believe (the remote vsv mounted on the valve cover, directly opposite the unit with the spring/screw/diaphragm). it is hidden underneath some hoses and the
wiring.
According to this diagram: http://web.archive.org/web/201004010...14layoutan.pdf the VSV mounted to the valve cover is for the PAIR. On Calif. vehicles it shows a second VSV for the EGR, but I only see one in Wallytoo's photos.
there are two on the valve cover. circled in yellow. the "green" one is for the "4wd pressure up" to apply/remove vacuum to the fuel pressure regulator. the egr uses a bvsv (bi-metallic vacuum switching valve), located at the front of the head, under the radiator hose. in fact, the layout that scope links to shows the egr modulator connected to the TVV (which i assume stands for thermostatic vacuum valve, but could be transmitting vacuum valve), not a vsv (vacuum switching valve).
there are two on the valve cover. circled in yellow. the "green" one is for the "4wd pressure up" to apply/remove vacuum to the fuel pressure regulator. the egr uses a bvsv (bi-metallic vacuum switching valve), located at the front of the head, under the radiator hose. in fact, the layout that scope links to shows the egr modulator connected to the TVV (which i assume stands for thermostatic vacuum valve, but could be transmitting vacuum valve), not a vsv (vacuum switching valve).
I'm pretty sure TVV (Thermal Vacuum Valve) and BVSV refer to the same component. (On the 3VZE, we have one to control the EVAP system, and due to its location is frequently broken. On the 22re, I think it's used only to control the EGR, as wallytoo said.)
The Fuel Pressure Control system (which VSV was pointed out by Wallytoo -- like I said, 22re's are not my forte) http://web.archive.org/web/201501160...ne/41fuelp.pdf is used to raise the fuel pressure under conditions of hot-start (by looking at ECT and ambient air temp). This is to reduce the risk of vapor lock. I'm pretty sure it has nothing to do with 4wd (why would you want higher fuel pressure then?). But the vacuum plumbing is as described by wallytoo; when the vsv is activated by the ECU, the FPR is connected to atmospheric rather than engine vacuum, which raises the rail pressure.
i don't know why it is called the "4wd pressure up" vsv, but that is what the FSM calls it. i've never chased out the wiring, either physically or in the diagram, but perhaps it only functions while in 4wd? not logical, but who knows?
The FSM page I linked to called it the Fuel Pressure Control System. I'm pretty sure that manual is nominally for the 1993 model, but it's been right on for my 1994. Do you have a different manual? Since the one I cited to is on the internet, we know that it must be correct. ;^)
For what it's worth, there is an additional ECT sensor in the water bypass for 4wd with 3VZE with auto with a/c. When the coolant gets too warm, a/c is shut off. But I don't think you're referring to anything like that.
the FSM i have is for a 1987. best i can see is that it notes that the fuel pressure vsv is present only in 4wd versions with efi. the FSM does have errors, and it's possible that toyota got the nomenclature more refined with each succeeding year. the under-hood label for the egr and other vacuum hoses shows the fuel pressure vsv being present in 4wd only, too.
there isn't anywhere in my FSM that shows the adjustable sensor attached to the upper plenum that connects some of the vacuum hoses to the A/C and the power steering, yet it is clear that that is what this piece of equipment does.
09-14-2013, 05:59 AM
