2012 Silverado 5.3 stock Idle Desired climbs to 800

[motichekg]

2012 Silverado 5.3
Stock engine with cold air intake.
no codes

Bought the truck with v4 deleted and minor changes to the tune. Compared to a stock 2012 tune and still cannot get the idle down.
When started rpms are normal 6-700. warms up to temp and idle is 500-550 range. Then shortly after the desired idle climbs to 650, then after the next redlight it will climb to 720, eventually stopping at 800 desired idle rpm and pushing through the brakes. All idle rpm tables are stock and even compared to another stock 2012 to confirm

Any idea what may be causing the desired idle rpm to go 260rpm above the main idle table?

the fuel trims are in spec, no evidence of vacuum leak.

spark around 15-20

attached tune file

[edcmat-l1]

How about post a data log of it doing it's thing?

[blindsquirrel]

Make sure the log has the ethanol % channel in it, since virtual flex is still enabled and has likely freaked out like they all do...

[motichekg]

How about post a data log of it doing it's thing?

[edcmat-l1]

That's odd. First thing I'd do if it came in my shop is flash it with a new stock file via SPS. When in doubt, wipe it clean.

[motichekg]

That's odd. First thing I'd do if it came in my shop is flash it with a new stock file via SPS. When in doubt, wipe it clean.

Just sent you an email

also trying to get the stock file from previous owner

[gtstorey]

Stock file in HPT format may not have the problem resolved in it since it doesn't contain all of the ECM segments in it.

[edcmat-l1]

Doing a write entire with a different HPtuners file, using HPtuners, is not the same as flashing it with a new SPS file.

[2xLS1]

Has the throttle body been cleaned. Try performing a throttle body clean reset with the scanner bi-directional controls.

[motichekg]

Has the throttle body been cleaned. Try performing a throttle body clean reset with the scanner bi-directional controls.

i have done the throttle clean relearn a few times. the throttle body is at the desired idle rpm, I just don't know what could cause my desired idle rpm to increase 260rpm over base warm idle.

[motichekg]

The fuel pressure in the log I uploaded earlier shows fuel pressure going to 43psi. Truck has no signs of fuel pressure issues or power loss. Is that Channel accurate?

[LS ROB]

Checked for vacuum leaks?

[motichekg]

Checked for vacuum leaks?

yep, fuel trims are good and commanded idle is where the idle is. Just dont know what would cause commanded idle to go to 800 on a stock file

[motichekg]

Doing a write entire with a different HPtuners file, using HPtuners, is not the same as flashing it with a new SPS file.

what would be needed to complete a new SPS file?

[2xLS1]

Here is a stock 2012 Silverado file with all the same segment numbers both ECM and TCM as the file you posted. I compared it to your file and I see nothing that would cause the "commanded idle speed" to change. That's not saying the idle speed is not increasing by some other means but everything in the idle tabs is completely stock. In fact most of the engine calibration is unchanged except for the DOD and some PE settings.

[2xLS1]

what would be needed to complete a new SPS file?

You would need some kind of pass through device and a subscription to SPS. Or pay to have a dealer or a shop that has that capability to do it. Expect to pay anywhere from $100 - $200.

[04silverado6.0]

Just for reference i charge 150 for sps programming. Anywhere 200 or less seems fair. I forget what the vin subscription costs.

[verlon]

Try this
base 2 NoIdleBoost.hpt

[motichekg]

im going to try this soon.

I did get some info from the previous owner and it was a diablosport tune. does diablosport change segments hptuners cannot access? may just get him to ship me the diablosport and return to stock that way?

[blindsquirrel]

You can check segment IDs and CVNs here--> https://tis2web.service.opel.com/tis2web/