Surging idle, sometimes

[CB7Man]

Like title states, my idle occasionally surges.
I'll be driving around, put the clutch in, and it will go between 1.5K and 1K
Then it will catch at 1.4K and idle down slowly to around 800 then it will bump up to 1,100 and then down again to around 750. But sometimes it hangs out at 1,100 and then goes up to 1,300 or so. But eventually it gets back to idle.

I've sealed every gasket with gasket sealer, replaced the IACV, ABV, fitted new vacuum lines.
I'm getting no codes...
A few mechanics suggested air in coolant
I never bled my coolant when I first swapped it.
I started it without the radiator cap on it and I let bubbles come out. Thats about it.
I thought it would cause serious idle issues if the coolant had air in it?

[Losiracer2]

you can try bleeding the coolant from that one bleeder screw on the T-stat. But what helped me was one of the hoses was kinked coming out of my IACV and I replaced that w/ a longer one so it wouldn't kink and it seemed to take care of the surging. And you already checked to see if your FITV was good right? By plugging the hole on the TB (h22) when the car is warm, you should have NO suction...if you do then there's a leak.

[CB7Man]

Are you talking about the Air Boost Valve? JDM engines have this blocked off, but I removed the block plate for emissions.
I just changed my IACV, it hasnt changed.
I dont really know how to bleed the coolant, lol just open the valve?

FITV is the one under the TB right?
How do I plug it?
Coolant flows through it.

[Losiracer2]

Are you talking about the Air Boost Valve? JDM engines have this blocked off, but I removed the block plate for emissions.
I just changed my IACV, it hasnt changed.
I dont really know how to bleed the coolant, lol just open the valve?

FITV is the one under the TB right?
How do I plug it?
Coolant flows through it.

yeah my JDM H22 has that block off plate on there also. Bleeding coolant is simple. Just wait til your car get up to operating temp, then unscrew that bleeder screw w/ a 12mm and watch the coolant come out. Once you see a steady stream then you can tighten it back up.

The hole i'm talking about is inside the TB. You'll see it once you remove your intake, when looking at the engine from the pass side, its the hole to the bottom left...basically an air intake for the FITV. You know your FITV is bad if you still feel suction when the car is at operating temp, b/c the FITV is only for cold starts and should only operate during warm-up, not when the engine is at operating temp.

[CB7Man]

yeah my JDM H22 has that block off plate on there also. Bleeding coolant is simple. Just wait til your car get up to operating temp, then unscrew that bleeder screw w/ a 12mm and watch the coolant come out. Once you see a steady stream then you can tighten it back up.

The hole i'm talking about is inside the TB. You'll see it once you remove your intake, when looking at the engine from the pass side, its the hole to the bottom left...basically an air intake for the FITV. You know your FITV is bad if you still feel suction when the car is at operating temp, b/c the FITV is only for cold starts and should only operate during warm-up, not when the engine is at operating temp.

That thing sucks my finger in!!
But this passage leads to the thing under my TB right?

[92 jdm h22a]

my ls/vtec used 2 do that. and i replaced the pcv valve and it quit. also the iacv could be messed up.

[CB7Man]

It was the air boost valve!
It rusted solid lol
I replaced it with the one from my F22 and it worked for a little bit, but now this ones rusted too!! wtf

I took WD-40 to the original one and it moves freely again, so I'll put it back on and see what happens

Also I tried plugging that other port and my engine was idleing at about 100 rpms haha

[jaykilla116]

what valve is that i have the same problem do i have a pic