Toyota Repair: rough idle, toyota 4x4 truck, 22re engine

Question
My question...My 1991 toyota 4x4 truck with a 22re engine seems to run and idle fine until I turn the air condition on.The idle becomes very rough and the engine will almost stall out when sitting still in traffic.The truck has 152,000 miles on it.It is a 5 speed manual transmission.

             Thank you
             Louie Banister  

Answer
There is an a/c idle up solenoid on the intake chamber it has a white knob on it with some hoses attached, the valve is adjustable, with the engine running and the ac compressor on turn the knob and see if the idle speed goes up, turn it the other way if it slows down, if there is no increase in speed you may have to replace this solenoid.