Power steering and AC idle up

[frank rabbets]

It's on the pump itself which you can get to by removing the front wheel then the vertical plastic mud guard.

 

[warrenpfo]

Frank the vacuum pump or the steering pump?

 

[frank rabbets]

On mine there is a valve on the steering pump.

 

[warrenpfo]

Ok Frank I think i am being a bit dumb as i cant see it.

 

[Rob]

It's on the banjo connector where the pipe connects to the pump.

 

[warrenpfo]

Thanks Rob, are we not confusing the vacuum pump with the steering pump here. Both in the same location only the vacuum pump is In front of the steering pump.

It has one larger and one small hose going from it and the large hose (runs to the brake vacuum cylinder on the passenger wheel arch up against the bulkhead in the engine bay) has a small black rubber pipe from the banjo that runs all the way up to the timing belt cover to the first vacuum solenoid or vsv.

If so then I have good vacuum from this pipe but I can't see how this activates the idle up for the steering as I would think it's more an electric switch that then opens the AC/steering idle up vacuum solenoid to then increase idle speed.

Yes I need a vacuum for the vsv to work and that is there but the switch or mechanism that activates the idle up when the steering wheel is turned at low speed is what I am after.

For those who know what I am on about does the pps solenoid or progressive power steering solenoid on top of the steering box have anything to do with the idle up or are they independent.

Thanks

 

[frank rabbets]

I'll go into this a bit deeper Warren. My steering does not power up the idle and I can't see anything on the fuel pump to do with the steering so perhaps they have removed it on some models.

 

[warrenpfo]

Frank the AC and steering idle up use the same vacuum solenoid valve that sits between the fuel filter and the fuse box.

The vacuum comes from a T in the big hose from the vacuum pump that runs to the brake vacuum reservoir and is constant.

There are two wires that plug into the vacuum solenoid and until you turn the AC on do not have a charge but on turning it on will open the vacuum solenoid and activate the idle up.

What I can't work out is where the switch is to activate the idle up for the steering.

 

[frank rabbets]

It could be that switch on the steering box. That might be connected to a torque sensor in the steering box so the engine will not idle up unless it senses that the engine is under steering stress as in turning the steering when the car is stationery.

 

[frank rabbets]

With this vacuum system there must be a vent for air to get out somewhere.

 

[Rob]

I was talking about the power steering pump Warren. There are a couple of small vacuum pipes that fit onto one of the banjo connectors on the PS pump. I have them but my steering idle up does not work, would be really useful if it did with the hydraulic winch.

 

[frank rabbets]

I think if you have that solenoid switch on the steering box you won't need and don't have power idle up. You will be fitted with pps which is purely a hydraulic system operated by ecus which detects vehicle speed and increases the power steering the slower the car goes. Engine power up is therefore not needed.

The pps system is described in RME-184 :-

SR- Steering
SR-28- Description of pps- Not all cars have it.
SR-56- Exploded diagram of steering box including pps solenoid location.
SR-65- pps system chart/diagram as to how it works. No vacuum nor idle up involved.

I have pps on mine so won't be looking for power up any further.

Does anyone have the alternative power steering system (not described in RME-184 that I can see).

 

[warrenpfo]

Frank you are the man. I think you have hit the nail on the head. I can confirm i have the PPS on my car and so like you won't be looking for the idle up any longer but will be making sure the pps is working as it should as on a number of occasions now i have stalled my car on the flat when I go hard lock.

 

[Towpack]

I think if you have that solenoid switch on the steering box you won't need and don't have power idle up. You will be fitted with pps which is purely a hydraulic system operated by ecus which detects vehicle speed and increases the power steering the slower the car goes. Engine power up is therefore not needed.

The pps system is described in RME-184 :-

SR- Steering
SR-28- Description of pps- Not all cars have it.
SR-56- Exploded diagram of steering box including pps solenoid location.
SR-65- pps system chart/diagram as to how it works. No vacuum nor idle up involved.

I have pps on mine so won't be looking for power up any further.

Does anyone have the alternative power steering system (not described in RME-184 that I can see).

Erm......not true. I have both on mine. The PPS operated by the solenoid (sits on top of the PSP with two wires coming out of it) and the vacuum servo operated idle up system and they both work. According to the 1997 sales brochure the PPS system is standard on the GX and VX (4.2TD only). This is for the last built Amazon badged 80's from '97>. I guess earlier vehicles could have either or both? In answer to Warrenpfo's question regarding what actually switches the vacuum through to the idle up servo when the steering is turned I have no idea.
One servo controls idle up for both AC and PS. The PS idle up is adjusted by the two 17mm nuts at the base of the unit and the AC idle up by the grub screw and 10mm locknut on the top.

 

[warrenpfo]

Towpack do you mean your pps solenoid is on top of your steering box and not your psp.

 

[Towpack]

Towpack do you mean your pps solenoid is on top of your steering box and not your psp.

Yes! Thanks for pointing that out Warren. If you have a twin pot idle up servo as I have described with two vacuum pipes then you almost certainly have PS idle up fitted.
If you want pics I can take some.

 

[warrenpfo]

No it's single pot. So maybe I don't have it and have to tell on the pps

 

[frank rabbets]

Hi Towpack

Pictures would be very useful so I can determine whether or not I have the power idle up. If I have it's never worked and the car was only 3 years old when I bought it. It's a 1995 VX 24 valve.

 

[Towpack]

As I understand it the PPS is linked purely to road speed and not engine speed. It just reduces the amount of assistance as speed increases irrespective of engine speed. The idle up system is to compensate for the increased load on the engine when turning the wheel at idle, parking etc, when power assistance is at it's greatest. JMO

 

[Towpack]

Hi Towpack

Pictures would be very useful so I can determine whether or not I have the power idle up. If I have it's never worked and the car was only 3 years old when I bought it. It's a 1995 VX 24 valve.

Just sitting down to lunch Frank so I'll post some up in an hour or so.