I have a 1999 honda civic EX, anytime I push the brake, turn on the a/c, even hitting the button to change gears in automatic the RPMs drop around 250 to 400 or lower then when I let go or any of them they go right back. Any help would be greatly appreciately.

New wires, plugs, cap, rotor, coil
Cleaned the Idle air control valve it looked pretty new to begin with.
I sprayed the engine down with carb cleaner looking for a vacuum leak and no rise on the rpms while spraying.
It only does this when I do something else that requires electricity.

If i put it in neutral or park and dont touch anything the rpm is a perfect 700 rpm and does not fluctuate at all.

 

Air filter is new,

I ran the checks on the Brake booster and bypassed the check valve it passed them. Plenty of vacuum and brakes work great there.

 

You may have a vaccum leak somewhere.. But im thinking this is an electrical problem..

Have you had any recent repairs before this problem started?

 

Unfortunately I am unsure. I bought the car a few weeks ago and it came with the problem. Originally thought it was the booster or check valve because I did not notice the issue with the other power usage other than the brakes.

The battery that was in the car to begin with had some dead cells in it and died completely by the time I got it home. replaced sunroof, fender, bumpers and other items mentioned before I checked into the idle issue.

It was hit in the rear passenger quarter panel, but I do not see many wires in that area that might have been damaged.

 

What does this have with Engine Management & Tuning?

 

a vacume leak would cause the idle to go up, or surge ac presure switch? is an electrical thing would suspect let me know if you find out.

 

rotary air control valve usually causes a surge in the idle but may cause your problem

 

I will look at the rotary air control valve or is that the air control valve? I cleaned the idle air control valve completely and the throttle body etc with carb cleaner. It seems to only be doing it now with the brakes, windows, and ac. it will drop by 200 rpm, then when turned off or released it will increase by about 700 for a minute.

I tried removing every fuse one at a time and testing and I can not get the problem to go away. Every fuse/relay that can be removed while the car is running seems to have no effect eliminating a lot of the wiring.

 

do you have a check engine light?? if so what is it?
sounds something similar to what i have in my 92 civic with a b20z swap.