Printable View
i am working on my 2017 ZL1. The scanner has this channel (Idle Desired RPM)and it is showing 848rpm at idle in gear. However, i have my Idle Base Setpoint set to 800rpm while in gear and when above 154degrees to 198degrees. So, why is the Idle Desired RPM saying 848 when i am in that temp range? What is bumping up the desired rpm?
ben, need some context here. you lost me at 17 ZL1. Without saying anything else or a signature I can only conclude you have a bone stock ZL1? Man or auto trans? Till I know more than that cant help other than if what you are saying is you are commanding an 800rpm but observing a variance of +/-50rpms? Ok.?
2017 zl1 auto with Magnuson 2650, BTR stage2 cam, NW103 TB, big gulp Intake, 2"ARH Headers with no cats, dsx aux low side pump.
So I am commanding 800 in the Base setpoint idle table but scanner channel says my idle desired rpm is 848. Why isn't it the 800 that I am commanding? It has nothing to do with my actual and fluctuations.. Just why is the desired not same as my commanded?
I believe the desired idle RPM is influenced by a few things. A/C compressor is one of them for sure as is Cat Lightoff. I've also seen desired higher than what the stock tune says on stock vehicles. I wonder if it is also affected by desired idle torque.
Ok, so when using a third party software tool to attempt to re-calibrate an internal combustion engine for which you have amassed a big pile of parts you are asking "Just why is the desired not same as my commanded?" Yet, you provide no scan or tune file to comment on? Do you really want to know "WHY?" or do you just want to be able to have the car do what you tell it like this is a dog obedience training session? Without proprietary knowledge that only comes with a signed paycheck from GM, we, use this tool and forum to try to help each other out. The only way I know how to try to provide help in a situation like this is by examining evidence provided. If you want any complex machine that is "aware," of it's dynamic environment you will need to let it know about the applied physical changes. That is, make updates that correspond to the static changes, the new rules, that you have applied with your wallet. You can have a "perfect," calibration tune file but, if any of the physical/mechanical/electrical elements are "off," you will get divergent from optimum results to say the least. Full context, not trying to sound like a dick, would like to try to help, just need more information.
Have you checked your startup and rolling tables? It will pick the highest value.
I did some testing and was surprised having AC on vs off made no difference. It appears that the Moving/Rolling Idle and/or the startup Idle were the culprits that work with Base idle. I should have done those one at a time to see which it was, but i did them both and now it desires what i have commanded. Thanks for the suggestions!!