Jump to content
Ultimate Subaru Message Board

Idle control circuit readings


Recommended Posts

Can anyone give me some info on iacv circuit meter readings? Like ohms out of the iacv itself, voltage to the valve from the harness at idle or key on only? It would be nice to have some reference points.

 

I'm troubleshooting a bad idle. Trying to figure out if it's the valve, or some issue with my harness. I can see that someone has done work on the harness before... If I turn my AC on, it idles better...

 

I read this thread and got some good info. I have the same issue. http://www.ultimatesubaru.org/forum/topic/145212-ea82-idle-issue-cyclic-idle/

 

 

20170521_175902_zpsdjh7ttrc.jpg

 

20170521_175917_zpsjkg6qqsn.jpg

 

Notice the larger and lighter colored wire routed to bypass the harness here

20170521_180003_zps075d5bet.jpg

 

 

See it going into another plug? Someone ran this new wire to bypass the harness

 

20170521_180005_zpsff1d88io.jpg

Edited by TheGageinator
  • Like 1
Link to comment
Share on other sites

The FSM has the details. I don't have one here. The iacv should click, and you can see the valve move if you have it off the throttle body, if you apply 12v to it's coil.

 

I once had a car where the wire to the iacv coil broke inside the harness on the engine.

Link to comment
Share on other sites

I checked out the valve today. I have 12v at the connector when reading across the 2 terminals. When I first start the car, if I unplug the sensor, it will die immediately. After the car warms up for a minute, if I unplug it, there is no impact at all on the idle or the way it runs... Still bumpy idle

Link to comment
Share on other sites

Measuring the voltage across the coil doesn't tell much.  The reading will be the same whether the coil is open or working.  The ohm reading for a good IACV coil is 8.6 to 10.6 ohms.  There should be open circuit from either pin to the body of the valve.  When the engine is cold, disconnecting the IACV coil connector will cause a large change in idle speed.  When hot, a smaller change.

Unplug what sensor?

 

The CTS can make for random idle and starting troubles.

The IACV I had fail open, caused the engine to not idle.  As soon as the throttle was released fully, it just shut off.  I could keep it idling by manually keeping the pedal down just a bit.

Link to comment
Share on other sites

miss at most rpms....   Not an idle problem.

 

Once the throttle is open some, the IACV has little effect on running.

 

Verify all the plug wires are good.  They can be check with ohms also.  Also, running in the dark, look for arcs.  These are 2 different checks for different problems.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...