need some help.


New Member
Nov 5, 2006
got some powerlogger values that i need som help with.
i tried to set my iac with my powerlogger and i couldnt get it
to set at 20-25 counts.

tried to set the idle at around 750. iac wouldnt register.ran the screw all
the way in to around 2200 rpm could only get it to register around 12 or 13 counts.
tried both ways "the unplug w/ computer in diag mode" and the set to
20-25 counts. if the veh is idling at 700-750,the iac registers 0

secondly, o2 is fluctuating wildly it follows injector cycle at idle
duty cycle oscillates between 3.2% and 3.9% is this normal or do i have one or mre bad injectors?

blm is bouncing at idle between 131 and 160. i would love to get this thing running right!

1) IAC does not adjust idle, chip does.
2) With car in Park, engine fully warm, A/C off, look at the IAC counts on the scantool. If you wish to lower the count number, turn the adjustment screw clockwise. To increase the counts, turn it counterclockwise. Turn the screw a small increment, turn the engine off, and restart. This insures that the IAC resets and confirms the adjusted number. Continue until the desired number is achieved. Often, on stock set ups, about 1-1 1/2 threads of the adjustment screw will emerge thru on the lever side of the throttle body. Restarting also rezeros the tps as stated in the prior section and removes any effect on idle speed that may have occurred due to tps movement. The IAC counts will probably be 30 counts, or more, higher on a cold engine than on a warmed up engine. The counts will also be much higher in gear as compared to Park, and, higher with the AC turned on.

Remember that the IAC adjustment will change the TPS and that if the TPS moves past 0.46 volts, the idle may increase in speed as the ecm no longer thinks the car is in idle range. Therefore, if you are going to decrease IAC counts very much, it is a good idea to first lower the TPS down to 0.38 volts or so in order to prevent it from rising out of the idle range as you adjust the IAC.

Set to 1 - 1.5 threads show.
turn car off
check tps & set
See where you IAC are at

You need to be concerned with the 160 BLM.
i did my homework before posting........
i adjusted the iac both ways as described on the gntype site.
this was as i followed the steps setting the iac using the scan tool......
at as i adjusted the throttle stop screw, (this is the iac screw?right?)
the iac counts moved only slightly. the rpms increase as you turn the screw,it contacts the throttle and pushes it forward. im not getting any
iac counts at idle around 700-750 im really not getting any counts at all.even to 2200 rpm.
if the chip/computer controls the iac then could i have a bad ecm or chip?

i adjust the iac the old method the second time...
pinned the aldl in diag mode.
turned the key to the on position .waited 30 seconds
unplugged the iac .
pulled the pin out of the aldl.
started the car.veh went to around 700-800 rpm.
turned the screw to lower the rpms to 500 +/- 50
rpm didnt go down when screw was turned.

what did do wrong guys? is there a specific torque on the iac i dont know about? ill reset everything. drop the screw to 1 and half threads, reset the tps. remove the iac.what do you think?

Just so you know. The more you raise the idle with the screw the lower the IAC count will go. Also, you need to pay attention to your tps while messing with the IAC because you want the ECM to know it's supposed to be idling.

Edit: It's going to be hell setting your IAC if you have vacuum leaks. If your blm's are hitting 160 at idle you probably have a vacuum leak.
thanks guys! i had a couple of vac problems.

egr.... i took it out of the loop and straight ran the vacuum line

and whoever rebuilt the engine had the vac to the turbo all screwed up.
got that taken care of as well

set the iac to 26 counts and the tps to .44 car runs much better but still
have a few problems temp is high at around 216-220. got the f body radiator and 160 thermo to install has trouble starting.....maybe fuel pressure is a little low. and im gonna pull the injectors and send them to chuck leeper. see if ive got some leaky ones.

heres a real potential problem i believe that the oil cap was blown off while i test drove the car today,i mean its freaking gone! ever heard of that? i dont want to even think about the reasons that happened !:eek: give me some feedback and thanks again !!!