My AC diaphragm holds vacuum and the idle goes up. When I shut the AC off the VSV closes like it's supposed to. The problem is my Idle up diaphragm maintains vacuum and when the AC load is removed from the engine the diaphragm remains engaged and my idle shoots up.

The shop manual mentions a procedure for checking the Idle up diaphragm. You check it with a vacuum....it states "check that the vacuum does not drop immediately"

I'm assuming this diaphragm is supposed to actuate under vacuum and release on its own.

I think I might need to replace the diaphragm....does anyone know where I can find a new one? Overseas, anywhere really. Or solutions (aside from just running without idle up)?


Thanks!

 

If the Idle Up Diaphragm holds vacuum, than it is good.

Make sure the linkage connecting to the diaphragm is not simply sticking.

I would go back and check the VSV.

The Idle Up Diaphragm is both activated and deactivated by the VSV, meaning that the VSV is responsible for supplying the diaphragm with vacuum when the VSV is turned in, and is also responsible for releasing the vacuum when the VSV is turned off.

When the VSV is turned on, the valve connects engine vacuum (port A) to the vacuum line going to the diaphragm (Port B).

When the VSV is turned off, the valve connects the vacuum line going to the diaphragm (Port B) to the atmosphere (filter C). In other words, the VSV should release the vacuum when turned off by connecting port B to the little filter on the side of the VSV.

Here is the factory Toyota manual for checking the VSV:

 

87yota

Thanks or the reply. My VSV lines were switched. I was blinded by the thought that vacuum lines never cross each other . The VSV lines definitely do cross!

Thanks again!