IAC Settings

[iju58u]

Hey guys,

Havent done much with my VR lately (havent even been driving it much..), but thought it was about time to get the tune sorted.. So i started with closing the Throttlebody and using the IAC as its meant to be. Had all sorts of dramas initially but after adjusting a whole heap of settings I got it to idle, but now the problem is I can't get the idle to come down below about 1400rpm?? I have the target Idle at 950rpm so not sure why its not even trying to get there? I've taken a quick log while idling if thats of any help. I also had O2 sensor issues but when I unplugged the factory one the car seems to use the aftermarket wideband for readings, is that right? can I just leave the factory narrow band unplugged? I know the AFR's are abit all over the place as its changing from open and closed loop etc but I'm trying to get the idle sorted first before getting the tune better. Thanks in advance

Dave

idling high.xdl

here is a quick log while idling if it helps..

(32.64 KiB) Downloaded 237 times

[antus]

Target idle is sitting at 950rpm in the log, but the engine is hanging around 1200, which usually means you have too much air getting past the TB (butterfly stop adjustment, or air leak) which needs to be physically corrected.

[iju58u]

throttlebody is closed completely i wound it right down, might have to doublecheck though.. thought there may have been something else i was missing. cheers

[VL400]

If you are running a close to stock engine have you tried a fresh cal file? I assume this is 12P too? If you can also post up the cal file your using it may help diagnose it further.

[iju58u]

gotta get some more time to play with it further i'm guessing antus was on the money on having a quick look it may be slightly on the stop rather than closed.. will update soon

[iju58u]

yep turns out the throttle was very so slightly cracked... got it idling much better now just need to fine tune it

last question though will the ecu be happy to use the wideband O2 signal? it seems to be happy?

*also motor isnt stock, crane 286, TorquePower manifold etc etc :p

cheers

Dave

[VL400]

Do the IAC steps change to control idle speed now? In your log they sat at 100 odd steps and never moved.