Trouble with idle speed in park

[srobertsfsj]

Hey guys,

One of the issues I am seeing is when engine is completely warm and I put it in park, it wants to idle at around 1300 rpm. I have done the IAC idle reset procedure several times and my TPS is at .54. Is there any bin paramters that would have an affect on this park idle speed when warm. It idles fine when cold. I tried changing "IAC Park Position" to 0 but it didn't seem to have any affect.

Thanks!
Scott R.

[PJG1173]

what mask and ecm are you using again? what are your IAC counts when it idles high? are there any vac leaks? have you knocked the plug out of the front of the tb and adjusted the throttle blade position?

[srobertsfsj]

Sorry, I should have given more detail.

what mask and ecm are you using again? I am using the $42 mask with a 7747 ECM.

what are your IAC counts when it idles high? The IAC count when it is idling high is 51.

are there any vac leaks? I do not see any vacuum leaks and it idles smoothly so I would say that is an safe indication that there are no leaks (but I could be wrong).

have you knocked the plug out of the front of the tb and adjusted the throttle blade position? Yes I followed the IAC reset instructions and used the idle adjustment screw to find my min. idle speed of 600rpm in drive (700rpm in park) but when I plug the IAC back in and restart the engine it idles high.

[RobertISaar]

it almost sounds like the ECM is purposely commanding that high of an idle speed.

don't suppose $42 outputs the commanded idle speed in the datastream, or at least someone knows the RAM location of it?

[EagleMark]

51 IAC counts is a little high but should work. It also indicates IAC is controlling idle and not a vacuum leak controlling idle. But a vacuum leak realy messes up MAP reading and adds fuel and messes up O2 reading and well vacuum leaks are not good.

Change all IAC paremeters back to stock for now.

When you do the IAC reset and IAC is all the way closed you pull IAC plug and set idle to 100 below commanded Closed Loop Idle if your bin is a closed loop idle bin and motor is well warmed up and in CL. Look for the Idle speed here "IAC - Desired C/L Idle Speed"

Do you have a Park/Neutral switch? Do you have a VSS? Did you clear codes after the reset and after setting timing? Do you have any codes after having no codes and driving around a bit? Is motor stock? If not what is vacuum at idle? Steady reading?

[srobertsfsj]

Do you have a Park/Neutral switch? Yes
Do you have a VSS? Yes
Did you clear codes after the reset and after setting timing? Yes
Do you have any codes after having no codes and driving around a bit? No
Is motor stock? Stock AMC360
If not what is vacuum at idle? 17
Steady reading? yes

I reset the IAC again, and i noticed that the IAC makes kind of a grinding noise when its reseting, is this normal? Also, I noticed that now my IAC is at 72 at idle.