My 85 22re has a very low idle. Runs fine otherwise. I have adjusted the idle screw and can only get about 800 rpm (using the dash tach). It's difficult to describe, but the engine seems to kind of cough to a start, jumping slightly to 1000 rpm and back down to 800. I was wondering if the IAC box is the problem, or if their was some other things to check? Thanks for any advice you might have.

 

Make sure your Throttle Position Sensor is adjusted properly, check out:
http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml
I had to pull the throttle body off to get at the lower screw on my '85. Helped alot.

Also make sure all vacuum lines are in the right places, this will cause idle/startup chaos if they aren't right, epecially if the egr is being told to route exhaust gas into the intake at idle when it shouldn't be...could just be a stuck open egr valve.
Check timing ,plugs, wires, dist. cap and rotor. I've been through it all on mine and the adustments yielded all of the improvement, not replacing parts.(unless you have some really bad plugs)