Cammed 5.3L high idle and cruise control issues

[Orange55GMC]

First time tuning, from a cold start the truck runs great and idles great until you shut it off and restart, then the idle goes through the roof on cold start and back down and basically runs 35 mph on cruise control until you brake enough to force it to idle down. If you blip the throttle in the slightest it shoots to 2200 rpm. Attached is a long first drive log and then a second log after the restart along with the tune and config file. Any help reviewing will be appreciated.

Engine Specs:

5.3L Summit Long Block ATK Performance
Summit Pro LS Cam .550 Lift 222/232 duration, 112 degrees lobe sep
TBSS Intake
Nick Williams 92mm DBC TB
Dougs 2 7/8 Longtube Headers 3? collectors
3 inch exhaust with x pipe and SpinTech Sportsman 3000xlp mufflers
4L60E w 3200 stall
3:73 Rear Axle

55 GMC.jpg

[2xLS1]

Tune is not that great. The VE has some unrealistic numbers in a block of rows and columns. The VE looks like it was just edited with a percent instead of tuning it with data. You shouldn't need to set tie in gear AC on idle speed at 1000 rpm. That cam shouldn't need any higher than 750 rpm idle speed with correct tuning.

[Orange55GMC]

Thanks for all the feedback, pretty much took your advice word for word and input those changes totally solved my 35mph cruise control issue.

[Alvin]

BRAF is a bit high and STIT is pulling some air away from the idle.

The TPS is not returning to zero is the issue I see in the log. 0.4% gets to be about the point where the PCM assumes your driving and when that is the case all idle trimming/learning is disabled. Pay attention to the TPS % and make sure it read 0 every time.

Some TPS's need a wrap or two of electrical tape to take up the slop in the fit between the sensor and the shaft.

[Orange55GMC]

BRAF is a bit high and STIT is pulling some air away from the idle.

The TPS is not returning to zero is the issue I see in the log. 0.4% gets to be about the point where the PCM assumes your driving and when that is the case all idle trimming/learning is disabled. Pay attention to the TPS % and make sure it read 0 every time.

Some TPS's need a wrap or two of electrical tape to take up the slop in the fit between the sensor and the shaft.

Thanks for the feedback, did exactly as you said now sits/returns to 0.0% and it also went from .64 to .61v.

[Orange55GMC]

Went back after considering all the feedback and fixing the tps issue and adjusted the VE and Idle tables. Also hooked up a wideband to the pcm to track through HPtuners, posted for someone who does the EGR Enable with older VCM version. Maybe take it out for some logs tomorrow morning. Thanks guys for the help.

53L 4l60e Summit Build.hpt

6.12.2025 idle TPS voltage issue solved.hpl