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I have a 93 4runner 3.0 auto, A/C. 4x4 and have never been able to get a response from the idle up systems for the A/C , or the power steering system. I have checked the vacuum routing repeatedly and it is hooked up right, but nothing. In the summer I have to up the idle to run the A/C and the power steering has occasional trouble with assist on right turns at idle. Anyone have any knowledge on getting this system to work? If I plug in the A/C solenoid for idle up it actually lowers the idle.
Thanks
Sounds like your vsv is receiving the proper signal and actuating. It also indicates the idle up valve might not be plugged up. Which just leaves your vacuum lines probably aren't hooked up correctly.
Both the idle-ups work by "short circuiting" metered air into the plenum, bypassing the throttle body. Both of them use the same paired connections. Start the engine, then pull one of the two hoses (A/C or P/S) from the connection ON the plenum. This admits unmetered air into the plenum, and the idle should rise. If it doesn't, that connection into the plenum is probably clogged (to be sure, put your thumb on it; it should be sucking with about 17" of vacuum.)
If the first step worked, get some short pieces of the right-size vacuum line (A/C is bigger than the P/S). Then connect the inputs to the outputs, bypassing the A/C VSV and the P/S idle-up valve. Again, idle should rise. If it doesn't, you have a clog in the metered air line. If it does, the problem is in the VSV and P/S valve (I'm guessing that's not it; why would they both go at the same time?)
Like everything else on your truck, it's a matter of starting at one end and testing until you get to the other. Staring at a vacuum diagram and insisting it's hooked up correctly doesn't advance your inquiry.
It looks like it is the a/c idle up line going into the plenum. Used some wire and carb cleaner and it seems to be working slightly. It's only a 50 rpm rise, but it's not dropping the idle anymore. You would think when the plenum was vatted it would have cleaned that port, but I guess not.I will just have to keep up with carb cleaner at regular intravals. Toyota uses a lot of egr re circulation that gums up small passages. There's only 24000 miles on the drive train.Just enough time for sludge to build up even with regular use of fuel system cleaner in the fuel. The power steering I believe its the idle up valve. Never has worked. Expensive little valve!
It's not the EGR, it's the PCV that is adding "sludge" to the plenum. Not that it makes a lot of difference to you, just don't use that as an excuse to poison the air by removing the EGR.
The 3.0 is heavily reliant on the EGR for keeping cylinder temps down (NOX). Anyone removing it is not doing their engine any good. I don't remove smog equipment and in fact go to great lengths to assure it is all working correctly. Not a lot of blow-by in a motor with 20000 miles on it. I could pull the plenum and show what the EGR puts in the engine. In fact there was a tread on here at one time showing a plenum from an engine with the EGR removed Vs one with a EGR and you would be amazed at how much sludge the EGR puts in the engine. Best thing is to run a fuel cleaner about every fourth tank of gas to keep deposits down and HP up. Need every bit of HP you can get in a 3.0.
Your pick shows you may have an issue with your rings and a faulty EGR. That EGR tube is rarely that clean. Is that from a new engine?
The EGR tube had been "recently" cleaned; this is a few months (a year?) of buildup. You can't see it in the photo, but the PCV tube makes a turn inside the plenum, so it "points" right to the spot on the tube where you see the crud.
Even several months earlier when I removed years of buildup, the crud was concentrated on middle of the tube (under the PCV circuit), and the end of the tube where the exhaust gases are introduced was relatively clean. So I don't believe the exhaust gases contribute a significant amount of solids.
But as to your issue, I too had so much crud inside the plenum that the idle-ups were not working. I cleaned it with solvent and degreaser in a mortar tub with bottle brushes. I did not remove the "freeze plugs" in the ends. In retrospect, I should have.
02-16-2019, 10:39 AM
