EFIDynoTuning Forum

Trying to learn how to tune using the A9L2 binary and the stock computer - and have been struggling with some behavior that doesnt seem normal or expected to me. No matter how much I increase the idle set screw (and stop/restart the engine) - I havent been able to get ISCDTY to drop below 0.28%.

However I can unplug the isc while the engine is running and see no change in the actual idle speed of the engine, which leads me to suspect its incorrectly thinking the isc is partial open?

I have been trying to adjust idle speed and the ISC so that the car can idle relatively smoothly and not stall out when coming to a stop/when cold. I seem to be able to get 2 of those 3, but not all 3 - and I am thinking it might have something to do with the ISCDTY?

I have done basic dialing in of fuel and MAF transfer - i think fuel still has some work to do but the adaptive when driving after some time are not far off (~3% or so) - so I believe I should be close enough to get the idle improved..

Any suggestions or things that jump out to anyone here that I am probably overlooking?

the ecu has no feedback from the iac position it only commands only

if the iac is at 28% and when you unplug it the engine doesnt respond that means you have a junk iac, time to replace it

yeah definitely sounds like your iac is bad