Love_00_Max

My PS is stiff at low RPMs and looking thro the repair manual, I found that there needs to be vaccum hose connected to the Air Control Valve.

In my case there is no vacuum and the manual details replacing the IACV. How does the IACV control PS and what checks I need in addition to vacuum present to determine IACV is actually working. There has been no codes logged by the ECM.

There was another thread where someone cleaned the IACV and messed up idles etc...

Any ideas as to where to start

P. Samson

You are mixing up the Power Steering Air Control Valve issues with the IACV issues. The Power Steering Air Control Valve uses "vacuum" to control the power steering hydraulic pressure/flow and the IACV is supposed to react to the change in vacuum when the Power Steering Air Control Valve is operating and maintain the correct idle. That's why this Power Steering Air Control Valve is mentioned in relation to the IACV. For what you are describing with your steering issue it is NOT, I REPEAT, NOT the IACV. To check the Power Steering Control Valve operation you simply check for vacuum at it's air supply hose on the intake airbox (I think it's the second largest hose) when you crank the steering off center and little or no vacuum when the wheels are centered.

madisonmxma

Another thing to do to see if there is a problem is to sit in the car with the engine running, and turn the steering wheel, the RPM should not drop off. The idle is stepped up to account for the extra load from the power steering.

Love_00_Max

Thanks Samson.

Now, there are 2 hoses connected to the airbox, one really tiny connected to a steel tubing from the airbox and then the other hose, larger one like 1/2", right below the tiny hose.

If I traced back the small hose, it winds its way reaching a fork tubing right next to the PS pressure regulator, the large hose goes to the crankcase towards the front of the engine where the air pressure valve is. On the tiny hose there is no vacuum.

Any picture would also help!!!

P. Samson

The Power Steering Air Control Valve is located just inboard of the passenger side strut tower, hidden under the power steering hydaulic pressure switch. It has the air supply hose and the vacuum hose attached to it. The vacuum hose originates at a black plastic elbow just downstream from the TB. You would not have by some chance "plugged off" the air supply hose if you installed an "aftermarket" intake?