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What exactly is this and how should it be adjusted? I played around with it a little bit so I'm curious exactly what it's function is and how is it supposed to be adjusted?
I believe that is the Air Control Valve for Power Steering. I looked in the FSM again and it only tells you to disconnect and connect the hoses. I haven't been able to find any info on adjusting it.
Okay let me know if you find anything on it! Not having any issues my idle is perfect, just curious. I have it screwed all the way in. Don't have any power steering issues either.
I currently have my belt off my AC, my clutch is bad and makes a horrible noise lol so I took belt off. I got a couple months until the heat forces me to take action.
Okay so since I have mine all the way screwed in mine shouldn't change much versus unscrewing it and letting rpm rise thus taking stress off pump? Interesting.. I'll have to mess with it some more tomorrow.
This is interesting. I wanted to see if I could get my RPM's to rise at the turn stops (tried adjusting the valve). Never did. Got in the car and was checking the idle, turned on the A/C and the idle would jump a little, but was not idling as before (thought I put the adjustment where it was) . Adjusted this and got the idle back up. As madfie said it does adjust for A/C also, or idle with a VSV open. Shagool, if it affects your idle I would think you have a VSV open or a vacuum leak. Still cannot find any place that tells you to adjust it.
Grumpin, that explains it now. After we had this talk^^ I tried playing with it again and it wasn't effecting idle like it was before. Just so happens the first couple times I played with it the vsv must have been open. I haven't played with it much since then. Still unsure where it's "supposed" to be set. Mine is turned all the way in at the moment. Yours?
Slightly increased idle speed when AC is compressor clutch
Is commanded on and or when the power steering Air Control Valve switches
from pressure at low speed PS pump operation.(Low speed steering).
Installed on trucks with Air Conditioning.
Its operation is not really critical especially in your case with your
AC inoperable.
Adjustment made with engine running(normal operating temp).
Adjustment is unnecessary if the vehicles AC is inoperable and or the
power steering air valve is inoperable. I would need to find one of my
manuals on testing for the valves and VSVs. Visual inspections are important. Unless its leaking the
the valve assembly not functioning doesn't really affect normal engine operation.
Now explain to me why when I turn the knob I can control the idle of my truck as if it were the idle adjustment screw? But, this happens only sometimes. Other times when I turn it nothing happens?
Here's a video of what I mean. Just captured this. Listen closely you can hear engine idle up or down depending on tightening or loosening the knob
Yes the idle speed will change some with its adjustment. But the effect in doing so is only seen when the AC is commanded or the PS air valve is commanded. Set the valve screw about center and adjust your idle speed with the "idle speed adjustment screw" on top the throttle body following FSM procedure of course.
Kiroshu it doesn't just change "some" I'm talking a range from 600 to almost 1500 rpm... Still not understanding Why sometimes I can completely control my idle and other times it does absolutely nothing..
Interesting. It has been a long time since I've needed to adjust one. I'm kinda confused however.. if its not a problem why are you still messing with it..?
If all parts of the fast idle assist system are not working then we have no reason to tamper. For example my 1986 4runner with AC and PS, the Fast Idle Valve is broken, the PS Air Valve is bad, and the AC is inoperable and these things do not affect the engines performance at all. They could I suppose depending on their failure, but eliminated from the equation yields no problems.
Because curiosity.. And I'd like for my truck to operate the way it's supposed to.
My AC is inoperable (belt removed until I replace AC pump soon) and I have no clue if PS air valve works or not. How do you test it?
Long story short I inherited this truck from my father with a blown engine. I rebuilt the engine and got it up and running again.. Only has 1200 miles on it at the moment. The truck sat (in a shop) for 15 years so I'm still working out some kinks. I have put a lot of time and money into this truck and I want everything to work as it should. I bought a donor 89 4Runner so I have extra parts.
Very cool I definatly understand that. Glad to see some people really putting time into their Toyotas.
Kinda the same way, I need parts for my AC($$$) as well so fixing the fast idle system isn't necessary yet. I was actually trolling through some of my FSMs I have laying around and there is not a lot of information on testing of the fast idle system for EFI engines. Imma keep looking though for my curiosity too haha. My 88 FSM and my 87 FSM didn't show anything but I have a bunch more to look through.
Yeah I hear you on the $air conditioning$.
My donor truck has one that might actually be good just haven't needed to put it in yet.
Let me know if you find any testing for the fast idle. I too have been looking everywhere with no luck! Thanks to you I now at least understand its purpose, good to know.
04-13-2015, 06:40 PM
