My 93 del sol with the 1.6 d16z6 engine is idling funny like for instance when i'm not putting a load on the engine the idle raises to 1500 rpm and then drops back down to about 700 rpm and reapeats this over and over i was wondering if it could be the throttle possitioning sensor but i'm not sure.

I took it to a mechanics shop and they told me that i needed an idle air control motor to even tell what is wrong with the idle but i can't see anything missing from the intake manifold at all. i don't know if the idle control motor is an external part or what.

Any Ideas? thanks