I own a 2000 civic with the above mentioned engine and it has bad idling habits with the AC off and it gets even worse when the AC is on. Also the car sputters when accelerating. I hvae got three questions, marked in bold:

The problem is as follows: When the AC is off and I am driving down the road and stopping, depressing the clutch, the revs drop to 800 rpm but then shoot up at 1300 rpm. Then it sits there for about 10-15 secconds and it falls back to 800 rpm, idling nicely. Why does it surge to 1300 rpms?

When the AC is on, it tends to get a bit more extreme. When I am stopping, depressing the clutch, the car almost seems to stall and the rev meter almost drops to zero. Then it surges up again t about 1300 rpm and after 10-15 secondsfalls back to 900 rpm. However, then the car starts to shake (which you can especially feel in the gear lever). Why does the rpm drop to about zero before surging to 1300 rpms?

Also, the car seems to sputter with medium acceleration aroung 2000 rpm. If I accelerate with full throttle there is no problem. When the AC is on this seems to get worse. Why is this?

The AC is original and has had a tune up a year ago (new coolant and stuff)

What I did so far:
> Clean the EACV and throttle valve by dismantling it and by spraying cleaner into the intake manifold
> Filling up the coolant level of the engine
> Revving up the car, but I already have a substantial driving style.

I hope you can help me! Thanks!

 

It could possible be Bad wires for the lack of power. As for the idle, if u have already tryed to clean it out and it didn't work then it possible that its bad. The shaking is just from when the engine drops donw on the idle and runs rough.

 

When I pull out the wires from the spark plugs, some of them have a rusty coloured powder on them at the end of the rubber, only the second cilinder from the right doesn't. However, the steel connectors that connect the wire to the spark plugs are fine and look brandnew.

For the surges I think I am going to try and clean and screw in my FIT valve, because I read a lot of problems regarding idling can be fixed by it. I also want to check and clean the pcv valve, but I cannot find it, anyone?

Thanks!