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That's kind of you. Just one clincher picture would do then I can follow the trail.
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Power steering and AC idle up
- Thread starter Rob
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Hi Towpack
I found it. I have the double diaphragm setup. The lower one and single pipe to it is the power idle up. The pushrod rises if I wedge the steering over with a stick and go and look. It falls just short of the throttle lever and hence does not work. I guess the pushrod would rise further if I unscrewed that screw in the top of assy? I think this might also increase the A/C idle speed though?
The nearest pipe, to the wing, goes to a switch which I think controls the A/C. It certainly clicks in accordance with the A/C going on and off and the pushrod rising. If I pull the pipe off the pushrod drops. The far pipe on the same diaphragm is a mystery. If I pull it off the pushrod drops presumably because vacuum is lost but if I keep the pipe off and block the metal tube the pushrod does not recver. There must be a small airflow over this diaphragm?
Any thoughts would be appreciated.
Thanks
Frank
I found it. I have the double diaphragm setup. The lower one and single pipe to it is the power idle up. The pushrod rises if I wedge the steering over with a stick and go and look. It falls just short of the throttle lever and hence does not work. I guess the pushrod would rise further if I unscrewed that screw in the top of assy? I think this might also increase the A/C idle speed though?
The nearest pipe, to the wing, goes to a switch which I think controls the A/C. It certainly clicks in accordance with the A/C going on and off and the pushrod rising. If I pull the pipe off the pushrod drops. The far pipe on the same diaphragm is a mystery. If I pull it off the pushrod drops presumably because vacuum is lost but if I keep the pipe off and block the metal tube the pushrod does not recver. There must be a small airflow over this diaphragm?
Any thoughts would be appreciated.
Thanks
Frank
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Warren that valve on the steering pump with the 2 rubber pipes operates the power steering idle up. On mine it goes to the lower of the 2 diaphragms. If I pull the pipe off the power steering idle pushrod drops down confirming . Mine does not work because the pushrod does not rise enough to open the throttle lever. The valve on the steering pump must sense when the steering is stressed through increase in hydraulic pressure. I think no electrics are involved. If I pull the A/C solenoid pipe off, the steering idle up still raises the pushrod.
warrenpfo
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Ok here is mine.
It is a single diaphragm version but am led to believe it does both AC and ps idle up.
Here is my power steering pump as in the diagram above in my first post with no vacuum doodaas on it at all.
Would love to see a picture of a steering pump with vacuum doodaa on it as I think we are still confusing steering pump with vacuum pump.
I am still hopeful I have idle up for steering as it does make sense that pps has nothing to do with idle up as if you in a parking lot and want to turn the pps will sense no motion and increase the flow of fluid from the pump but as the pump on the later model like mine is direct drive one has to increase revs to get faster flow and better steering.
It is a single diaphragm version but am led to believe it does both AC and ps idle up.
Here is my power steering pump as in the diagram above in my first post with no vacuum doodaas on it at all.
Would love to see a picture of a steering pump with vacuum doodaa on it as I think we are still confusing steering pump with vacuum pump.
I am still hopeful I have idle up for steering as it does make sense that pps has nothing to do with idle up as if you in a parking lot and want to turn the pps will sense no motion and increase the flow of fluid from the pump but as the pump on the later model like mine is direct drive one has to increase revs to get faster flow and better steering.
Towpack
Well-Known Member
Adjust the PS idle up first using the two 17mm nuts until the the pushrod/actuator contacts the throttle linkage just enough to give the correct idle speed increase when the steering is turned, then tighten the nuts. Then switch on the AC. You may find the idle speed increases significantly so adjust for correct idle-up speed using the small screw adjuster and 10mm locknut at the other end of the servo unit. Even though the servo unit only has one pushrod/actuator the PS and AC idle speeds are independently adjustable.
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Towpack
Well-Known Member
Ok here is mine.
It is a single diaphragm version but am led to believe it does both AC and ps idle up.
Here is my power steering pump as in the diagram above in my first post with no vacuum doodaas on it at all.
Would love to see a picture of a steering pump with vacuum doodaa on it as I think we are still confusing steering pump with vacuum pump.
I am still hopeful I have idle up for steering as it does make sense that pps has nothing to do with idle up as if you in a parking lot and want to turn the pps will sense no motion and increase the flow of fluid from the pump but as the pump on the later model like mine is direct drive one has to increase revs to get faster flow and better steering.
Going on the info in the FSM, if you have AC and only have a single pot/diaphram servo unit it is unlikely you also have the idle up system for the PS
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Warren I'll post a picture of my power steering pump with the hydraulic switch attached, you don't have power steering idle up by the look of it.
The pps will sense no road speed when you are parked and tell the pump to deliver more pressure to the steering box making the steering lighter for parking. I would have thought.
Thanks for the info' Towpack. I've been meaning to investigate the steering idle up but never got around to it. I understand what you say about A/C and power steering idle up adjustments being independent and that they have to be done in the correct order. I don't think I need to adjust to get it working as I've never had a stall.
I've been working on my ACSD and found out exactly how that works and a possible danger if it is not fully working. I'll post separately.
The pps will sense no road speed when you are parked and tell the pump to deliver more pressure to the steering box making the steering lighter for parking. I would have thought.
Thanks for the info' Towpack. I've been meaning to investigate the steering idle up but never got around to it. I understand what you say about A/C and power steering idle up adjustments being independent and that they have to be done in the correct order. I don't think I need to adjust to get it working as I've never had a stall.
I've been working on my ACSD and found out exactly how that works and a possible danger if it is not fully working. I'll post separately.
warrenpfo
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agreed which is a shame but maybe its a Jap import thing.
The pump can only deliver more pressure if the revs are increased as there is a direct relationship between the two as the pump is direct drive.
I can see how the pps solenoid may open fully if the car is stable to give the steering box full flow rather than having some of it diverted like when under way.
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Here's the picture of the switch on the power steering pump. One of the pipes from it leads to the lower of the twin diaphragm chambers as shown in Towpack's picture. I have the same twin assy.
My steering is fairly light when I turn it lock to lock on idle with the car stationary. If I increase revs and do the same there is no difference so I don't think there is any point in adjusting it to work.
My steering is fairly light when I turn it lock to lock on idle with the car stationary. If I increase revs and do the same there is no difference so I don't think there is any point in adjusting it to work.
Towpack
Well-Known Member
I think the system is there to prevent excessive idle speed drop from the PSP load when parking maybe with a large electrical load on the alternator. If I disconnect the PS idle up and turn the steering when stood the idle speed drop is barely discernible, if at all. With all the electrics on the speed drop IS noticeable. Maybe just Toyota going slightly OTT to cover all eventualities? Whatever, if it's fitted, why not have it working?
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Towpack
Well-Known Member
......all you'll need is the PS hose with the banjo/adaptor for the switch, the switch itself, the twin pot servo unit and a bit of vacuum hose. Given the probable cost of that lot new, probably not worth it but with good used parts maybe.
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Has the fact that Towpack's and Franks are manual version and Warrens is an auto any relevance to this "Idle Up" discussion as there are differences on the ancillaries on the IP as I recall ?
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Well I've had a close look at my steering idle up and it opens the throttle very slightly when the engine is fully warm and the ACSD is away from the throttle lever.
Hi
I have 1995 October 80 man with 1hdft with double actuator not operating on air con idle up
After many attempts i found the vacuum control switch on back of pump failed, replaced with second hand ok
also found that vacuum lines had mud blocking, have now cleared and have vacuum to both diaphragms on actuator - power steering idle up works fine but not A/C idle up so I replaced Actuator set 26133-17841 with new
Still no operating. I have founf that if the power steering idle up is operating i can then adjust the idle up further with adjustment screw on top of diaphragm
There is only 2 x vacuum hoses, 1 from power steering pump air switch to bottom actuator and 1 from vacuum pump line to 12 volt air con switch to top actuator
From the top actuator i have 2 pipes with 1 blanked off
Has anybody have any suggestions on what i am missing, Im actually wondering if the new actuator is faulty
If i apply vacuum to bottom actuator rod moves to allow for idle increase, but when i apply vacuum to top actuator no movement of rod ( except if bottom actuator has vacuum then there is slight movement, but this only allows for A/C idle on top of power steering idle up speed)
I have 1995 October 80 man with 1hdft with double actuator not operating on air con idle up
After many attempts i found the vacuum control switch on back of pump failed, replaced with second hand ok
also found that vacuum lines had mud blocking, have now cleared and have vacuum to both diaphragms on actuator - power steering idle up works fine but not A/C idle up so I replaced Actuator set 26133-17841 with new
Still no operating. I have founf that if the power steering idle up is operating i can then adjust the idle up further with adjustment screw on top of diaphragm
There is only 2 x vacuum hoses, 1 from power steering pump air switch to bottom actuator and 1 from vacuum pump line to 12 volt air con switch to top actuator
From the top actuator i have 2 pipes with 1 blanked off
Has anybody have any suggestions on what i am missing, Im actually wondering if the new actuator is faulty
If i apply vacuum to bottom actuator rod moves to allow for idle increase, but when i apply vacuum to top actuator no movement of rod ( except if bottom actuator has vacuum then there is slight movement, but this only allows for A/C idle on top of power steering idle up speed)
PeterLC
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Hi,
I'm new to this forum so let me introduce my LC first. It's a '95 80 with 1HDFT and manual transmission and 240KKms on the odo. It's a heavy duty version, without any luxury items but with a 24V starter. I love the way it cranks and starts in a fraction of a second.
To the point now, the PS and AC idle up actuator has two diaphragms but also two unconnected rods each loaded with a spring. The lower PS diaphragm is connected to the external rod that you can see moving when you use the steering wheel. It retracts against its own spring until it reaches the rod of the AC diaphragm. If you apply vacuum on top of the AC diaphragm (switch on the AC), this one will move up. If the PS rod was against it (i.e. the steering wheel being turned), then it will move higher increasing idle speed more. But if the steering is not being used, the PS rod will just remain in the extended position whether the AC is on or not because the rods are not connected.
This should answer Bigcars question although it might not be relevant anymore. Also Frank's question about the leak in the diaphragm. can be answered. Ther is no leak in the diaphragm but in the chamber between them. This chamber is connected to the vacuum pump over the PS switch but also to atmosphere over a small filter located near the PS oil tank. This connection allows the PS idle up actuator to return to its normal position when not turning the steering wheel. It exlains why you see the actuator's PS rod move slightly up and back down when you apply AC vacuum.
I figured this out because I installed an AC on my 80 and it's not cooling well in the dessert at 650rpm idle. I imagine it the car could stall at idle in terrain with AC and PS in use without idle up.
I'm new to this forum so let me introduce my LC first. It's a '95 80 with 1HDFT and manual transmission and 240KKms on the odo. It's a heavy duty version, without any luxury items but with a 24V starter. I love the way it cranks and starts in a fraction of a second.
To the point now, the PS and AC idle up actuator has two diaphragms but also two unconnected rods each loaded with a spring. The lower PS diaphragm is connected to the external rod that you can see moving when you use the steering wheel. It retracts against its own spring until it reaches the rod of the AC diaphragm. If you apply vacuum on top of the AC diaphragm (switch on the AC), this one will move up. If the PS rod was against it (i.e. the steering wheel being turned), then it will move higher increasing idle speed more. But if the steering is not being used, the PS rod will just remain in the extended position whether the AC is on or not because the rods are not connected.
This should answer Bigcars question although it might not be relevant anymore. Also Frank's question about the leak in the diaphragm. can be answered. Ther is no leak in the diaphragm but in the chamber between them. This chamber is connected to the vacuum pump over the PS switch but also to atmosphere over a small filter located near the PS oil tank. This connection allows the PS idle up actuator to return to its normal position when not turning the steering wheel. It exlains why you see the actuator's PS rod move slightly up and back down when you apply AC vacuum.
I figured this out because I installed an AC on my 80 and it's not cooling well in the dessert at 650rpm idle. I imagine it the car could stall at idle in terrain with AC and PS in use without idle up.
Hi there everyone! New member here. This is an old thread but help would be appreciated.
I own a 1HDFT H151f 80 series. The car was stalling a lot, especially at stops and stationary turning of the wheels. I did some research and checked my PS and AC idle up calibration. To my surprise the AC idle up vacuum hose had been unplugged, I plugged it back in and immediately the rod pulled back in and my idle went up to 850. So it all went well!
I drove the car with the Ac on and it didn't stall however turning the steering stationary caused it to stall. I checked the PS vacuum hose at the opposite end of the AC hose and it felt like it was there. I traced my finger along it and I turns out the hose had been cut off and it was squeezed so tightly that there wasn't any vacuum leak.
If you've read this far please bear with me.
1) I don't know where to plug this end of the hose to. So any help would be great help. I've looked at the 1hdft vacuum diagram but im guilty of not being wise enough to understand.
2) Secondly I blocked this hose off with a screw to prevent any vacuum leaks but now my AC idle up isn't working anymore either, as in the rod isn't pulling itself back anymore.
There is vacuum in the VSV, there is vacuum at the opposite open end of the PS incomplete hose. But it isn't still working. Any thoughts?
Any help would be of great value and cheers in advance to anyone willing to help out
I own a 1HDFT H151f 80 series. The car was stalling a lot, especially at stops and stationary turning of the wheels. I did some research and checked my PS and AC idle up calibration. To my surprise the AC idle up vacuum hose had been unplugged, I plugged it back in and immediately the rod pulled back in and my idle went up to 850. So it all went well!
I drove the car with the Ac on and it didn't stall however turning the steering stationary caused it to stall. I checked the PS vacuum hose at the opposite end of the AC hose and it felt like it was there. I traced my finger along it and I turns out the hose had been cut off and it was squeezed so tightly that there wasn't any vacuum leak.
If you've read this far please bear with me.
1) I don't know where to plug this end of the hose to. So any help would be great help. I've looked at the 1hdft vacuum diagram but im guilty of not being wise enough to understand.
2) Secondly I blocked this hose off with a screw to prevent any vacuum leaks but now my AC idle up isn't working anymore either, as in the rod isn't pulling itself back anymore.
There is vacuum in the VSV, there is vacuum at the opposite open end of the PS incomplete hose. But it isn't still working. Any thoughts?
Any help would be of great value and cheers in advance to anyone willing to help out
