Sorry, One other thing I forgot to mention,
On the opposite end of the manifold to where the throttle body sits, you will see a device ( not sure of the correct name for it, some sort of adjustable modulator perhaps???) with vacuum tubes connected to it and a spring loaded knob in the bottom of it., they are tied in with the ISC valve and to another electrically operated vacuum switch mounted on the firewall.
On the electric vacuum switch, do a quick check with your multimeter to make sure the switch is operating. From memory, I think it has voltage applied to it when the A/C is off and no voltage when the A/C is on. ( again, the manual will show you in more detail)
Also, just check all those vacuum lines to eliminate the possibility of a split or broken line making the idle speed go crazy. In particular, the big vac hose that runs from the ISC valve to the other end of the manifold. Mine literally crumbled when I disturbed it!!
I'm seriously thinking of buying a load of shares in one of the companies that manufactures vacuum hose. With all these people working on old toyotas, (camrys in particular) there's a fortune to be made!!!!!!!!!
Bookmarks