`92 VX idleing problem

[4bfox]

Hi: Well, I've been reading the VX threads here, and checking my car against the suggestions. Came across the PCV valve issue, where the VX version is different from the other Civic PCV valves, i.e. no spring, plunger, etc.

Then I remembered my mechanic saying something about the VX engine swap we just finished, about it having "the wrong PCV valve, with no insides". Cracked open the hood, and sure enough, he replaced the "right" PCV valve with the "wrong" one. So I took the "wrong" PCV valve, cut off the plunger/spring end, removed the "guts", and reinserted it.

Fired it up, and immediately noticed the engine "surging" from about 1000-1300 RPM. I drove it a little, and noticed a lot of black smoke from the exhaust. Went on the highway, put my foot in it and the smoke cleared up. Came back in town, drove around some, still "surging", around 800-1000 RPM. No more smoke, though.

I'm wondering if it's a dirty IACV? I visited with our mechanic again, he said he had a terrible time getting it to idle, before he replaced the PCV valve with the "wrong" one. He also mentioned the plugs in the new(er) engine were black...like the mixture was too rich...

Any other suggestions?