I had to advance my spark to keep the car from dieing on me and i get rpm spikes when at idle. I've cleaned the unit once but no change. The idle reving goes away after driving for a bit. But then it will sputter to accelerate from idle to about 1800 rpms when accelerating.Distributor, cap and rotor, plugs, wires are new. Any ideas?

 

FITV. If you have a 92-00 civic it is located on the bottom of the throttle body and you should make sure you clean it and screw the unit all the way in and back it out 2-3 revolutions. this fixed my idle problem but do some research as to what you are getting into and where it is located in your vehicle. RonJ has a really good tutorial link if you get lost.

 

As mentioned, click the FITV link in my signature.

Also check whether your coolant level is low and then bleed the cooling system.

Have you checked for vacuum/intake air leaks?

Is the CEL ON?

 

THe thermo valve had to be replaced when I put thenew 1.6 cause of high idling after the engine warmed. So I wouldnt believe it to be that. But the more I think about it. I do notice after a while of driving the idle will stop revving up on its own (which happens in park or nuetral too. But turning the lights on solves this.) and bad weather worsens this.

 

Inspect the spark plugs, wires, cap, and rotor.

 

You mention it is a new engine, is everything put together tightly? Vacuum leaks anywhere (for example between the manifold and the head, or the throttle body and the manifold) will cause rpm to increase. All the hoses on right? I think when it warms up it tries to purge the canister and if that isn't right it'll be a big leak. Is your ECU the right one for the engine size?

 

The cap, rotor, wires, plugs are new but I checked them out anyway. Look fine and the gaps right. I cleaned the FITV with a brake cleaner so it was alcohol based so it would dry itself out. But it seemed clean enough too. I mean when I idle the rpms climb then drop and repeats, then it will sputter to accelerate for about 1000 rpms..

 

The ECU is the match up, swapped with motor, I did put the s200 in though, but it was months ago and this is a new problem. CEL is only throwing o2 sensor2. I noticed my heat shield is loose and I have a very small exhaust leak before the CAT. DOubt this would cause all this, right?