idle up

[bravekozak]

I need help. I bought a Toyota idle up valve and solenoid off of the Bay.
On my custom throttle plate I have a vacuum diaphram. When vacuum is applied the throttle pulls down further.

I need the idle speed to increase when the air conditioner is on or the power steeing is cranked and the pressure is up.

Correct me if I am wrong. I believe the way it is supposed to be installed is the threaded portion to the intake manifold for full vacuum. And a hose between the the side barb and the throttle dashpot. I believe that as the electrical signal comes to the solenoid from the A/C, it causes a plunger to move and open up the valve so more vacuum can pull the throttle lower. I assume it does this proportionately.

Here are pictures I took of the assembly today from both sides.

http://bwbronze.com/festiva/idleup1.jpg

http://bwbronze.com/festiva/idleup2.jpg

[iceracerdude]

Show the throttle body and make sure you show the dash pot and the vacuum diaphram.
Or is that the diaphram in the picture you're refering to?

[bravekozak]

dashpot

Here is the picture of the throttle dashpot.

http://bwbronze.com/festiva/dashpot.jpg

As you can see, the Toyota barb is a lot bigger than the Ford KB laser barb.
As I said, the goal is to convert an electrical signal from the A/C or P/S into a proportional vacuum flow to pull on the throttle a little, so the engine won't stall at idle/low engine speed under load.

I am not certain of how to adjust the idle up. I presume the screw with the spring will provide pressure against the primary vacuum source. What is that black thing on the solenoid? Some knd of pressure release? Is it adjustable?

[iceracerdude]

I would think that vacuum "pull off" in the third picture would up the idle as the vacuum hit's it's highest point, which of course is at idle.
The black thing on the electrical valve is some kind of air filter vent. Once you plumb that thing into a vacuum source, the power to the electrical switch either opens or closes that air valve. Yeah, you can't just assume that valve is always closed and then opens when the power is applied. I too would think that's the case, but you need to check that function first. Show the place on your car where you're going to use this.

[bravekozak]

firewall

I applied current to the solenoid and it clicked open, allowing the vacuum to flow. I am going to screw the dashpot on the back of the intake manifold where the EGR was. I am going to use a 1/4" to 1/8" pipe adapter. The solenoid will be mounted just above it on the firewall. I will connect a hose with a tube reducer, between the solenoid and the throttle bracket dashpot. I will post pictures when I am finished.
I need to know where and how to tie in to the A/C an P/S circuits. I am using the Sanden dealer installed air. Does anyone know how that little brass prong works on the power steering pump anyway? Is it based on varying electrical resistance based on pressure?

http://bwbronze.com/festiva/pump2.jpg

I am using a 1989 wiring harness.

[bravekozak]

no PCM

Power steering pressure switch

The switch's function is to signal the PCM when the power-steering system exceeds its normal operating hydraulic pressure, like when you cut the steering wheel all the way to one side and hear that hissing sound from the pump. The PCM then raises the idle speed and/or disengages the air-conditioning compressor to prevent the engine from stalling.

I do not have a PCM. How would I wire it to cut out the air conditioner? Anyone know?

I now know why there is only a single wire going to the pump.
The power steering pressure switch is a simple on/off switch. The ECU sends voltage to the switch through the blue/yellow wire. With engine running it should see the voltage as long as there is no steering input. Turn the steering wheel and higher pressure should close the switch which should send the voltage to ground. The ECU is looking for this voltage to change. If the cicuit is continously open or shorted it knows there is a problem in the PSPS circuit. You should be able to back probe the wire and measure the voltage to test the circuit.

It looks like I am going to need something to send 12V to the idle up solenoid and cut the A/C at the same time. I wonder if the old cars had something like that? Time to look in my 81 Malibu shop manual.

[bravekozak]

computers

Would anyone know if one of these computers would monitor the power steering pump valve for ground and relay 12V to the idle up solenoid?

http://cgi.ebay.com/ebaymotors/1984-1985-Mazda-RX7-RX-7-Power-Steering-Computer_W0QQcmdZViewItemQQhashZitem3c96cbcffeQQitemZ260227977214QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

http://cgi.ebay.com/ebaymotors/86-88-Mazda-RX7-RX-7-Power-Steering-Computer-Brain_W0QQcmdZViewItemQQhashZitem588034deebQQitemZ380108070635QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

[bravekozak]

answer

I found the schematic. That computer is not what I am looking for. But, I encourage you to visit, just to find out what a properly worded disclaimer should be!

http://www.myacrobatpdf.com/8454/1989-mazda-rx-7-factory-service-manual-steering-system.html

Now, maybe someone can post a pdf of the Festiva manual.