Jump to content
Ultimate Subaru Message Board

Recommended Posts

So I've been doing some trouble shooting with my high idle issue with a GL-10 turbo. From everything I've seen on the form it looks like the CTS is the culprit and do to time line I've already got it on order. So when looking at the thermostat there is only a 1 wire sensor at the bottom of that. The only 2 wire sensor I was able to locate is a third of the way down the rad on the passenger side. The connector looks to be the same as what I'm searching out. one of the wires is in series with the A/C fan though which tells me this is switch rather than a sensor.

 

The only replacement vids I've been able to find are N/A models and have the two wire sensor under the thermostat which does not match what I'm looking at. Attached some photos of what I'm looking at.

 

post-71386-0-34623300-1526770240_thumb.jpg

post-71386-0-40499700-1526770242_thumb.jpg

Share this post


Link to post
Share on other sites

The CTS cannot be on the radiator, that is something else, probably the fan sensor.

 

I can only look at the diagram in my FSM. The CTS looks like it is on a coolant duct - cast aluminum thing - behind the intake manifold. On the thermostat side of the engine.

Share this post


Link to post
Share on other sites

The CTS is not ypur high idle culprit.

The ECU in turbo cars does not control idle speed according to coolant temperature  like a SPFI car does.

 

Have you:tried adjusting idle speed via the large brass idle speed adjustment screw in the throttle body?

Share this post


Link to post
Share on other sites

Just from memory the CTS is located on that crossover pipe under the intake manifold right side of the throttle body. a real bear to get at. 

Share this post


Link to post
Share on other sites

Hotwire or flapper air flow meter?

 

Both have a fast idle control device but differ from series one flapper to series two Hotwire

 

High idle means it is getting more air bypassing throttle body butterfly

Share this post


Link to post
Share on other sites

Hotwire or flapper air flow meter?

 

Both have a fast idle control device but differ from series one flapper to series two Hotwire

 

 

 

No they don`t.

Both turbo engines use the same AAV(auxilary air valve)  for high idle on a cold engine.

No CTS involved.

Share this post


Link to post
Share on other sites

+1 You could also have an air leak between the MAF and the throttle body. I missed a line on the intake boot once and she idled right up

to 2K.

Share this post


Link to post
Share on other sites

CTS is Bosch style 2 pin connector.  No pigtail, harness clips straight to it.  "natural" color.  In front of turbo area, in the crossover pipe portion of intake.

 

test if the idle issue is AAV related.  Pinch the hose.  If idle drops, then you're AAV is stuck open or leaking.

 

I've just capped of a few of them.  Then set the idle with the screw in the back of the throttle body.  Might mean needing a tad bit of foot throttle on very cold days to warm up, but otherwise works fine and is less annoying than a constant high idle.

Share this post


Link to post
Share on other sites

Going to be tearing into it tonight to have a look at the suggestions you all listed. I'll report back once I have a look.

Share this post


Link to post
Share on other sites

Looks to be a combination issue. Found a few vacuum leaks that prompted me to replace all of the vacuum lines with new as they were all brittle and weren't sealing the best. Also looks like the previous owner took the cap off the AAV and didn't do a good job of resealing because it was apart and filled with junk. Cleaned it out but it was late last night so didn't start the car as the exhaust is not assembled so it's loud and i didn't want to wake my neighbors. So we'll see how she runs tonight. 

Share this post


Link to post
Share on other sites

The AAV was already adjusted as far as it would go to lower idle so my guess is it's either leaking or seized. I'm going to follow Gloyale's advice and just clamp the hose and be done with it. Probably needs to be pretty cold for this to make for hard starts with the hose clamped. 

 

Thanks for the help all !

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×