Surging Idle

[skate4life]

1993 ex d16z6 4dr. When you start the car it idles at like 2k rpm which is normal when cold but when it warms up alittle. it continues to idle at 2k but it keeps going to 2k the droping to 1k but as soon as it hits 1k it goes back up and keeps doing it over and over and over, very annoying. it does it worse when it is sitting still but does alittle while it is moving with the clutch in. I figured it was the iacv but don't know how to adjust it. My question is what could this be? am i correct with the iacv? how do you adjust the iacv if it is that?
thanks for all the help.

If i need to i could try to get a sound clip

[CxHatch]

Most likely the IACV, But you dont adjust it. Take it out and clean it, or just put a new one in.

[skate4life]

today i unpluged it while it was running and the idle didn't change, does that mean it is no good or just clogged with shit?

[crazyskills]

it is only a few bolts i would clean it and see if that makes a diffrance. if not maby try to adjust it alittle.. i have not really had much of a problem with this and when i have it was always easy to make it stop.. good luck.

[Haysoos]

FITV I bet. If you look at your throttlebody, its on the bottom. It'll be held on by two bolts, and when you tak it off, coolant will spill out. Not much.

When you have it off, there will be a plate on one side (points at the firewall before you take it off), take that plate off and screw the plastic piece inside down. It's wierd, on the outside, it has the notches to screw it in, but not on the inside, so you'll need two screw drivers and/or some imagination. Screw it down snug, not TIGHT. Hook everything up and see if that fixed it.

Had the same problem on my engine. rev. rev. rev. rev. Theres a thread I posted on here with pictures. Somewhere.

Good place to start if the IACV is fine.

[red97tj]

also check the vacuum lines...i had a similar problem after i did a zc swap. i finally chased it down to 2 vacuum ports that i was supposed to plug up. i used a short piece of tubing along w/ 2 screws pushed in at the end. well the threads on the screws let a bit of vacuum leak...so i just used 2 screws that didn't have threads that go all the way to the top of the head.
good luck.

[big_g_jando]

had that same problem with mine it was a broken vac line... its a easy fix but you just got to findit first

[Gassaver]

today i unpluged it while it was running and the idle didn't change, does that mean it is no good or just clogged with shit?


I'm curious about this myself. Because I can unplug mine and the idle won't change and it is suppose to.