Usually 10-14 degrees

 

Update; Just installed another used IAC valve from flynmiata. Idle improved a bit but when hot its still rising a bit. I can also see the ecu is trying to lower the idle value but it's not helping. Any other suggestions?

 

Below a certain idle value duty cycle of 70 or so the valve will actually shut off. If the ECU goes to lower values there is no effect. If the value is below 70 this means you need to close your manual idle valve on the throttle body more which will increase your idle air control valve's overall effort. This will raise the minimum value needed to keep the engine running keeping you out of the 70 range where the valve may stop working.

 

Travis, they work down to at least 15% DC. if you set the minimum to 70, it's going to idle at 3k.

 

I think it may depend on the year. With my 92 valve if I let it go below ~55 it starts to stall.

 

Every car I've worked with pretty well stops at the latest around 60% or at least stops acting "monotonically" I believe is the term I've heard batted around. Maybe you do get performance down to 15%, but the closed loop controllers aren't going to like it.

When customers start having weird idle issues and their idle effort is around 65-70% I always tell them to close the valve on the throttle body a little more and increase their open loop idle effort to compensate. This generally fixes weird stuff like good cold idle performance but hot idle is too high and permanently floats in that area despite their DC going down by 20% or more to compensate.

 

You ever get this worked out?

 

New used IAC vavle helped but it still idled higher than usual, then it went away without me doing anything else to it. Idle screw is pretty close to being closed though, when before it was turned much further out.

 

I hate phantom problems like that....no pun.

 

necro!

Travis,

I owe you and the rest of the idle problem victims an apology. My idle valve only works reliably from about 65% on up.

While I swear I got it to do something at some point at 15%, I can't seem to repeat it, but 65% seems to make the whole thing much more stable. No more lugging the engine when the A/C kicks on because adding 5% to 15% = no change in idle but adding 5% to 65% results in a nice rpm rise before the compressor engages.

 

Is this the Min. Value % DC in the Overall Control box?

 

yes. try 65 minimum and 100 maximum and see how she goes.

 

Going from 20-100 t0 65-100 makes the idle up more consistent when the ac comp. engages. It would ocassionally do it before now it seem to work every time. Much better.

 

I read something old recently on the adaptronic forum that I think should of been mentioned in the advanced idle tuning instructions and would have saved a lot of grief. I read that you should turn the idle bypass screw 20rpm less than the optimum idle speed. This is so the ICS is always controlling how much air is coming in.

In the advanced idle tuning instructions it says to set the screw at the optimum rpm.

Here's the thread with a how to tune idle. http://adaptronic.com.au/forum/index.php?topic=232.0

 

keep in mind that minimum idle speed changes depending on air density which changes depending on weather conditions. I bet it varies 1-200 rpm from hot summer to cold winter.