Ok so I Baught my civic the other day it has a d16z6 swap I did a air intake clean nd my rpm jumped from 1000 to 1800 and when it gets hot it would bobble between 700-1700 over nd over when I would idle I adjusted the small bold on the air intake under the cable and it lowered my rpm it then started to grab and is sticky on my pedal the auto zone guy told me to take off the throttle control valve and clean it when I did it started to idle better when cold idles to low when hot went for a 70 mile drive filled up before I left and I have a half tank gas left please help me get my mpg bac !!!! I'm new to Hondas so :/

 

Well, if you messed with the idle before cleaning the IAC valve, your idle may not be set right. The motor SHOULD idle a bit high when cold, then drop to 'right' RPM levels when warmed up some. On my 97 DX it seems to drop about 500rpm when it starts to warm up.

Your IAC may still be dirty, for one. As for the mileage, your gas gauge is not a good indicator. The only way to even somewhat accurately measure your gas mileage is to fill up, drive it for a while, fill back up, and do the math.

 

Do not adjust that small bolt attempting to control idle speed. Its purpose is to let the throttle plate close fully but not slam shut. So reset it to that condition. As you found out, if the bolt is too far out and letting the throttle plate slam shut, it will get stuck. It is supposed to be adjusted once at the factory and doesn't need to be touched again for the life of the car.

The ultimate idle speed is controlled by the ECU and the IACV and isn't adjustable. Any tinkering you do under the hood will be met with feedback from the ECU to return it to where it is programmed to be. If the engine is not stalling out the idle is OK. If it idles too fast, too much air is entering the intake for some reason such as a vacuum leak or the IACV stuck open.

There is an air bleed screw in the top of the throttle body that influences the range of control the IACV has. It is an aluminum core with a large slot for a flat screwdriver. If you have a two-wire IACV the adjustment of that screw is as follows:
Warm up the engine. Turn off the A/C and all electrical devices other than the engine.
Unplug the IACV plug. The idle should drop real low (450 rpm) but not stall out.
Adjust the air bleed screw to achieve the 450 rpm.
Plug in the IACV. Idle should increase back to the normal 750 rpm.
(Don't trust the dash tach to read idle speeds. If you don't have a service tach, just adjust for almost stalling out but not actually stalling.)