Chirp coming from intake

stb · Postby **stb** » Mon Aug 12, 2013 2:02 pm

Assuming my noise is the same as OP's, it can't be the EGR valve - I don't have one installed. I also recall that I didn't have the problem before I went closed loop idle control - with no ICV/IAC valve connected there wasn't a noise.

project.r.racing · Postby **project.r.racing** » Mon Aug 12, 2013 7:56 pm

PT wrote:I'm thinking you could be right. Might try adjusting it slightly. From memory don't you need to bridge two points points in the diagnostics port to adjust it correctly?

Dunno what you are attempting to do by adjusting it. but whatever you do, it will still make the same noise if it is fully operational.

PT · Postby PT » Sun Aug 18, 2013 4:10 pm

Ok, so I've gotten rid of the chirp.

Some time ago I adjusted the idle as low as it would go by fulling closing the idle adjuster, I was able to lower it to 1000rpm. By opening it up and now idling at 1100 rpm the chirp is completely gone.

However, this means I have another problem, there is air getting in somewhere which is keeping the idle up. Anyone have any thoughts on where to look? I've visually checked the obvious vacuum lines, is there a common cause of this?

Thanks
Paul

Postby **Okibi** » Sun Aug 18, 2013 5:13 pm

Can you take some photos of the engine bay? Might give some more ideas.

There's a few lines that connect onto the intake manifold near the canister, inspect all around there and see if any have come off.

project.r.racing · Postby **project.r.racing** » Sun Aug 18, 2013 7:33 pm

PT wrote:Ok, so I've gotten rid of the chirp.

Some time ago I adjusted the idle as low as it would go by fulling closing the idle adjuster, I was able to lower it to 1000rpm. By opening it up and now idling at 1100 rpm the chirp is completely gone.

However, this means I have another problem, there is air getting in somewhere which is keeping the idle up. Anyone have any thoughts on where to look? I've visually checked the obvious vacuum lines, is there a common cause of this?

Thanks
Paul

did you put it in maintenence mode when adjusting the idle base? as far as i'm aware, 1000/1100rpm is too high. should be 750 +/-50 rpm.

i hazard a guess that all the attempt to adjust thing, now the iac is always open so some degree (most likely the reason for the high idle rpm) which is why you ain't hearing it open and close.

if you have a air leak after the AFM, then it will idle lower than normal, and even be irregular rpm due to loss of vacuum through the AFM.

PT · Postby PT » Mon Aug 19, 2013 7:38 am

Yes I followed the correct idle adjustment procedure. My current thinking is that when I cleaned the throttle body with Subaru Upper Engine cleaner I may have inadvertently stripped the seal off the throttle body which is letting a small amount of air past.

Standard idle is 850, I'm sitting around 1050. I can adjust it down to 1000 and then the chirp comes back.

Will try and source a new TB.