I got a 2000 honda civic lx, and it vibrates during idle.

I changed plugs, wires, filters. It got little better but still vibrates.

So I clean the throttle body, IACV w/ carb cleaner.

but now, whenever ac fan turns on rpm goes up to

about 1500 and drops back down.

I think I might have damaged IACV while i was cleaning it.

(I found out I'm not supposed to use carb cleaner while cleaning
IACV because this stuff can damage it, if the stuff gets into the
electrical part of iacv)

Does anybody have any suggestions or what else could be wrong?

 

rpms should go up when the AC is on.

 

rpms should go up when A/C cuts on...however, you should not have a fluxuation in rpm...like 500 to 2000 to 500 to 2000 to 500....you get my drift. that revving is usually the IACV not doing its job. Yes you can damage one by "cleaning it" with carb cleaner or brake cleaner. most of those are very caustic chemicals and as such damage the weak diaphragm inside the IACV. They only way to know for sure if it is the IACV is to replace it. They can be pretty pricey though.

 

I cleaned mine the way you did, but allowed the IACV to sit over night before putting back in. Don't forget to check your coolant level.

 

if it is surging like that, than you need to turn in the internals on the FITV. It will also smooth out your idle.

 

man i am lost what is the fitv

 

Fast Idle Thermo Valve. Its the thingy hanging from teh bottom of your throttle body. There will be a removable cap with a "nipple" you need to take off that cap and then using a flat head screw driver, thread the plastic internal back down snug.

 

thanks for clearing that up for me

 

i was going to recoment the fitv also since when i first put in my motor the car was running at 3grand and took almost a month of changing parts until i found out about that damn plastic screw