Idle Air Control Valve Cleaning... Problem..

[J_S]

The superdo's hasn't been running so well lately. Here's some background: 1995 legacy l 2.2 mt 240,000 on the car and i'm told about 150,000 on the engine (bought it from a shady mechanic..). The car has trouble idling, usually a low, rough idle (to the point of stalling a few times) and a surging idle. This winter it threw a MIL for the upstream O2 sensor. I replaced the sensor with a bosch universal sensor, maybe not the best choice. A few weeks ago it threw another MIL for cat below efficiency. At this point i'm thinking the cat is bad so i ordered a bosal replacement. While it is shipping, i figured it would clean out the throttle body and the idle air control valve in case those were the reasons for the idle problems. Pulled off the iacv and was very surprised to see there was no lower port on the valve. Hard to describe but check out the pictures.

 

 

[sEE REPOST BELOW FOR PICS]

 

 

I'm not sure what to make of this, perhaps someone else has some insight. I certainly don't think it's a major issue since the car was running fine previously. Could the intake manifold be from another engine/model? How would you recommend I clean this iacv? Lastly, any suggestions as to the cause of the idle issues would be greatly appreciated!!!! Thanks!

Edited May 5, 2011 by J_S

[lmdew]

You picture links go to google.mail?

[J_S]

Sorry about that. I reposted them on flickr.

 

Throttle Body and IACV

 

IACV, the gasket indicates that there should be two ports but there is only the one.

 

Intake Manifold, notice there is only one port for air to enter the manifold.

 

 

Here's the flickr link too incase those don't post.

http://www.flickr.com/photos/62601096@N08/

[MilesFox]

Your problems may be related to the coolant temp sensor, as this component directly affects when the idle air ontrol valve opens and closes.

 

If the car thinks its warm, the idle will be bad when cold, and the IAC will not be open.

[94Loyale]

As far as the IAC, that is how they look. Just one port, it is correct.

[jboymechanic]

If you do wish to clean the IAC, this is the procedure from the FSM

 

1. Start and warm up engine until radiator fan operates

2. Hold throttle open so engine runs at 2,000 RPM

3. Disconnect bypass hose from IAC

4. Slowly pour one 16 oz can of cleaner (Sea Foam is good) into bypass air hole

5. Leave the engine to run for 5 minutes

 

When you do this expect lots of white smoke from the exhaust. When you're done don't forget to re-attach the bypass hose to the IAC.

[johnceggleston]

If you do wish to clean the IAC, this is the procedure from the FSM

 

1. Start and warm up engine until radiator fan operates

2. Hold throttle open so engine runs at 2,000 RPM

3. Disconnect bypass hose from IAC

4. Slowly pour one 16 oz can of cleaner (Sea Foam is good) into bypass air hole

5. Leave the engine to run for 5 minutes

 

When you do this expect lots of white smoke from the exhaust. When you're done don't forget to re-attach the bypass hose to the IAC.

 

this is good.

 

now, what does the bypass hose look like??

 

thanks.

[94Loyale]

They must be talking about the big hose that goes from the intake tube to the IAC.

[jboymechanic]

They must be talking about the big hose that goes from the intake tube to the IAC.

 

Yes, exactly.

[yewman]

Hello,

i have a 1999 legacy with 2 litre engine. Although the engine runs fine,

the warning light comes on sometimes. I checked the codes, and number 24 , the IAC valve comes up.

 

I removed the grey plastic solenoid cover, shown in the photos in this thread.Inside was a small amount of metal shavings sticking to the magnet.

 

I didn't go any further as I didn't want to damage anything, but can you pull the moving part of the solenoid out with the cover/electric coil bit removed?

 

Are there any pics of what the metal rod /armature should look like, as I don't know where the metal shavings came from.

I re assembled the valve, and the engine works fine.

In the UK, a complete valve costs nearly as much as the car's worth

Thanks

Yewman

[Fairtax4me]

Probably nothing. Wipe the shavings out with a rag and put it back together. Be sure to set the position of the solenoid exactly where it was before or it will cause problems.

 

Cleaning the Idle valve is easy with a can of Throttle body and Air Intake cleaner. Very effective stuff. It will also lubricate the inner workings of the valve.

[yewman]

I did clean out the shavings, re assembled and kept the solenoid position as it was. The engine still runs well, and has just passed the government emissions check which is part of the annual test in the UK.

The engine light still comes on sometimes.

As you suggest, I will get a can of intake cleaner.

Not sure who sells it over here.

Thanks

Yewman

[TBFK]

I had the DTC P1507 pop up, and all I had to do to fix the issue was remove the IAC Valve, and the PCV Valve as well as the hoses connected to it, then sprayed them all with brake cleaner. Just spray some brake cleaner in the IAC Valve and PCV Valve, shake the living hell out of it, drain, and repeat as much as you want. As for the hoses, you can do the same thing, but you can also take a baby bottle cleaner or pipe cleaner, and run it through the hoses. you could also just buy new hoses as well.

 

However, if the CEL comes back, I'll go buy some Sea Foam and clean it out the right way.

[silly]

Hate when no answer  is given;

 

Shorted lead for the harness. Everything tested out clear for voltage, so i didn't follow that lead.replaced the harness, Just throwing ideas, after all, multiple valves were tried, all cleaned...

 

New harness, still no go.pulled on the wires some, so the crimps were out of the way... Presto... been running ever since.