92-94 honda accord idle problem

Check for vacume leak including intake. Spray some carb cleaner around intake and vacume hoses and listen for engine rpm to change.

A defective idle air control valve will keep the idle too high.

it will do that, it is normal, should go between about 600 and 1500 rpm...
----------- thats just a normal warm up cycle, it will change the engine speed and mixture as combustion gets better with the heat.

turn the idle screw down on the carburater

)The fact that thge engine idle fluctuates when it is cold indicates that the Fast Idle THermo Valve is out of adjustment.
This valve is located ot the front of the intake manifold on the driver's side just below the accelerator cable. To adjust it, wait until the engine is cold (best to do it first thing in the morning).
Remove the two screws holding the cover on and start the engine. There is a brass needle sticking up through a plastic ring that has two slots in it. With the engine idle fluctuating, use a thin flat blade screwdriver to SLOWLY turn the ring CLOCKWISE
until the idle stabilizes. Once done. put the cover back on withg the two screws and you should be done.