H22 Jumpy Idle at stops

[ATK_Designs]

My According is having weird problem lately. During warm up, the car idles fine, a little low (~700rpm), but it's ok. However, after a short driving, the idle keeps bouncing between 1100rpm and 600rpm at traffic stops.

I cleaned the IACV, check the Dizzy cap, idle screw, etc. But it's still the same.

Can anyone shed some lights?

Thanks.

[punkr6]

sounds like the IACV, sometimes cleaning it won't do the trick. any CEL's ?

threee most common causes of idol surge are
1-bad iacv
2-vacum leak
3-timing

borrow a friends iavc and see if thats it...

[1SOL2NV]

sounds like the IACV, sometimes cleaning it won't do the trick. any CEL's ?

threee most common causes of idol surge are
1-bad iacv
2-vacum leak
3-timing

borrow a friends iavc and see if thats it...

dry rotted hose maybe ?

[Tech5]

I have one if needed, also try letting it run and tap on the IACV see if its stuck done this many times, you might need to spray some silcone spray or WD 40 inside it and then tap on it and should help

[01CDMLUDER]

First:
Check your coolant level- Any air bubbles in the coolant will cause a fluctuating idle. If its low, top it off, then CORRECTLY bleed it
Second:
Check for vacuum leaks- Go over all vacuum lines connected to the intake manifold, looking for cracked, corroded or disconnected lines . Spraying soapy water on the lines while the engine is running is a popular and effective way to find an air leak.

Next:
To isolate a bad FITV/IACV/vacuum leak-




*Note: the FITV is only located on the bottom of the throttle body on H23/22's. For F22's, its on the front of the intake manifold*


To fix the FITV:
-Take it off the throttle body with 3 10mm bolts and 2 coolant hoses.
-Take the gold/bronze cap off the end with 2 phillips head screws. You'll see a wax ring/plunger under the cap; screw this down as far as possible, then back it out half a turn. Thats it. Then reassemble.

To fix the IACV:
-Take it off the intake manifold with 2 10mm bolts and 2 coolant hoses.
-Clean out all the screens/filters with some carb cleaner/seafoam, then reinstall.

Lastly:
If none of these fixed the problem, clean the throttle body: Sometimes carb buildup between the throttle plate and TB will hold it open slightly, causing fluctuations.
-Take the intake off, and disconnect the coolant hoses for the FITV (where applicable) and take the throttle cable off. Disconnect the connector for the TPS on the back of the throttle body.
Take the TB off the intake mani with the 2 12/14mm bolts and 2 nuts. Clean the carb buildup off the entire throttle plate with some carb cleaner/seafoam, both opened and closed. When the plate is opened, make sure to clean the mating surface on the TB


Sorry the pictures are soo big but they're hard to see otherwise. Hope this helps

[ATK_Designs]

Thanks guys, I'll look into it again this weekend. Awesome posts. Repped everyone.

Another another note, I noticed that my coolant level was low so I topped it off last weekend. How do you go about properly bleed it though?

Thanks again.

[punkr6]

Thanks guys, I'll look into it again this weekend. Awesome posts. Repped everyone.

Another another note, I noticed that my coolant level was low so I topped it off last weekend. How do you go about properly bleed it though?

Thanks again.

check it again after a few heat cycles and you will be fine..

[ATK_Designs]

Interesting notes:

1. The bouncing idle is now more "Frequent" after I cleaned out the IACV and topped off the coolant. Before, it usually starts after a "long" drive, but now, it starts almost immediately after a short drive.
2. This fluctuating is not permanent. It bounces a bunch of times at the stop, then idles fine afterward.

Do I need to readjust the idle afterward? Someone mentioned to disconnect the electrical plug on the IACV after the engine is warm, adjust the idle screw, shut the car off, cleared out the ECU (Disconnect the battery over night), replug the IACV and resume normal operation?

[yellow ek]

Refer to 01CDMLUDER's post and adjust the fast idle valve(FITV). That is usually whats wrong if cleaning your IACV didn't work. It's simple just like his diagram shows.