iac steps
should the iac steps remain where it is set? i set the iac to 6 with the car warm and after a few revs it remains at 6. after the ignition is cycled and re-started the iac goes up to 20. then keeps going up everytime the car is restarted. this is done in about a 10 min period so conditions and temp remain about the same.
Yes, the steps fluctuate. Set between 15-20. As long as your engine gets back to your target idle, the IAC is doing its job.
If I apply a little throttle I get a better start. Logic says the engine needs more air at crank so would it be approperate to increas crank iac? Also what is the difference between increasing crank iac and increading crank iac mult?
Quote from Knick68 on April 5, 2019, 2:01 pmIf I apply a little throttle I get a better start. Logic says the engine needs more air at crank so would it be approperate to increas crank iac? Also what is the difference between increasing crank iac and increading crank iac mult?
If the engine runs without pedal, you have enough air. Plus the IAC opens up when you start engine to aid starting. I would look at your fuel side. Prime shot and Cranking.
I find that start tuning is the hardest to get correct. There are many varying factors between engines and aftermarket parts.
With cold engine there is an instant fire but just for about as long as it takes to think it will run and key is turned to run from crank. Then it dies. If it is cold and I add just a little throttle before cranking it fires right up. It usually starts on the second try without any additional throttle. Starts pretty well when warm.
Quote from Austin DeHaas on February 20, 2019, 6:36 amYes, the steps fluctuate. Set between 15-20. As long as your engine gets back to your target idle, the IAC is doing its job.
So the Ultimate LS fitech kits should be set between 15-20 steps? Everything I've read from Fitech says 3-10 steps (which is where im at).
Is it different for the ultimate ls kit?
Thanks I'm just trying to chase a backfire issue.
Quote from 68firebirdlsx on September 11, 2019, 2:11 pmQuote from Austin DeHaas on February 20, 2019, 6:36 amYes, the steps fluctuate. Set between 15-20. As long as your engine gets back to your target idle, the IAC is doing its job.
So the Ultimate LS fitech kits should be set between 15-20 steps? Everything I've read from Fitech says 3-10 steps (which is where im at).
Is it different for the ultimate ls kit?
Thanks I'm just trying to chase a backfire issue.
I have found around 15 steps works better. Ultimately the steps should never hit zero. Using Fitech suggestion was not ideal.
The unit I'm working on I had set the IAC to 7, drove it for a while, starts stops. Shut offs and start. Now the IAC sits between 0-3, turning the throttle screw doesn't do anything. The idle is still at 840. When you say set it at 15-20 the screw would fall out on my unit. Please correct me if I'm incorrect here. According to Fitech you adjust the throttle screw while the engine is idling at operating temp. I've done that. Turned the screw with the engine off, turned key on send to ecu, wait for the screen to go dark. It just doesn't respond. It likes to stay at 0 most of the time. Do I need to change the idle speed setting?
Thus far tuning this after the reading the instructions from the fitech site hasn't been a problem guess I spoke to soon.
Mike