setting Idle on the 12P code

[benk]

I am having some problems getting the Idle below 1000rpm on my Turbo V6 in the buggy.
I am running the 12P code in it
It looks like for some reason the IAC is keeping the rpm above 1000rpm at Idle when at operating temp the IAC sits at around 57-59 steps. I have the rpm set at 750rpm in the IAC tables for RPM V battery voltage for park/nutral ect have tried raising and lowering these and dosn't seam to make any difference.
I would have thought that the IAC would have kept closing off until the desired rpm was reached or it reached zero?
Is there something I am missing or something else that would keep the idle up?

[Jayme]

can post a log? what does desired idle speed in the log say? are there any error codes? got a pic of your buggy?

[benk]

The desired Idle starts at about 950 when cold down to 750rpm once upto temp but the actual rpm sits at around 1000 and dosn't seam to want to go below that. It isn't coming up with any codes (only 13 but that is because I don't have the O2 sensor hooked up at the moment)
I will do some logs and post it up
I am in the process of uploading some photos at the moment

[vnsswithcam]

what idle advance are you running?

[benk]

what idle advance are you running?

Are you talking about the idle spark timing?

[antus]

Theres probably too much air getting in past your throttlebody somewhere. Check its all sealed up ok and there are no leaks. If there are, then too much air gets in, fuel gets added, and even when the IAC is completely closed your rpm wont drop down as much as 12p is wanting.

[benk]

I will have another look for air leaks but I don't think the IAC is closing fully (it sitting around 57 to 59 steps. If the IAC was fully closed wouldn't it read 0 steps?

[vnsswithcam]

idle advance in my vn ss was set at 26 deg??? and id want it to idle at 750rpm but wouldnt go that low then i changed idle advance to 16.88 deg or something like that and idled perfect after that but check for leaks and check your fuel maps if they all ok adjust idle advance if still idling high put vehicle in diagnostic mode and check if iac fully closes it should if it doesnt the worm drive in the iac may have worn teeth so the motor is working but the pintal isnt moving could be your problem??

[VL400]

Yeah 0 steps is closed, 50 odd steps sounds like its not in closed loop idle and waiting for all conditions to be met - really need a log to be able to see whats not being met.

[Holden202T]

sounds like something else is wrong to me .... if the IAC is commanding 58 steps theres a problem right there ....

usually what i find is if the butterfly is too closed it will open up the IAC (more steps) and if the butterfly is too far open you'll find the IAC steps go to zero in an attempt to get the idle down.

i would suggest removing the IAC, give the hole and the end of the IAC plunger a good clean with carby cleaner etc and make sure the IAC is actually moving.

you should be able to fairly easily test by key on and off (not starting) and the IAC should move and then park once the key goes off.