alconk

Just curious on how the IACs work on my 82. I replaced mine a couple years ago with new AC Delcos but noticed looking down where the plunger is and tapping the gas they do move but when they come back it's not a smooth action. It's like a controlled stepper where you can see each step coming back rather than a smooth transition if that makes any sense. My other ones did exactly that. And even though color doesn't make a difference mine are black where as the others along with my old ones were cadmium. So is that the normal operation or should the action be a smooth motion?

Buccaneer

The IACs are a stepper motor for a controlled vacuum leak, but you probably knew that. Yes, they should move in and out smoothly since their movement in/out is in counts which are rather small movements. Are you getting a CEL at all?

alconk

It's probably alright and no CEL. It's just so damn slow for the idle to settle down to 650 rpm. When I come to a stop it will idle around 900 but if I sit there long enough the idle will drop to the 650 range. It's always done that though.

billschroeder5842

Sounds normal to me; mine does the same. It never crossed my mind that there was something the matter.

alconk

Ok well I've never been able to compare it ti anyone else so thanks. Just wished it would react faster.

billschroeder5842

At this time of the year I run my AC almost non stop. I note that the car will idle up when I initially put on the AC.

Normally my car idles at 650ish with swings of 50 here and there. When I put on the AC it will jump up to 950ish and settle down to 650 again after a bit or my waiting at a stop.

When cold, the car starts and idles at 1000 until a bit warm then 650.

I'm not sure if it is normal or not, it just is what is happening.

terry82

mine does the same thing always has. have been told that a chip can change that.i have noticed the warmer it is outside the less it does it.

billschroeder5842

Ok...With three '82s all experiencing the same 900ish to 650ish range, I pronounce us "normal."

Now, if I could only get my wife to agree that I have something normal about me.

alconk

Well there you have it then. Thanks and good luck with the wife lol..

Buccaneer

On a cold start the idle should go to around 1,000-1,200ish and drop to normal as the motor warms up. Normal is wherever you have it set at, but 650ish works fine. When the AC is turned ON and compressor clutch is engaged, the idle should increase, this is the ECM AC ckt, pin 21. It increases due to load. This is also normal.

Here is a good article on IACs and troubleshooting them. Good read. Good luck.

terry82

I pm ed you what up

alconk

Now I forgot to ask but when these rpm #s are being thrown out is that when it's in "D" or "P"? I drove mine today to watch and my idle in "P" is 850-900 but in "D" it's 650-700. Is that too high? Or is the 650-700 range suppose to be in "P" and around 500 in "D"?

billschroeder5842

Yes, Yes and Yes on mine.

I will get similar RPMs whether the car is in Park or Drive and with or w/o the AC.

It seems to move around a bit and then settles down.

This is a fuel injected car the the idle and rpms are computer controlled-- I really don't worry as long at it all smooth out at a point.