idle surge

[gmcserg]

whats up people long story short 2014 sierra 5.3 got camshaft replaced due to lifter issue
truck has 3400 stall long tubes ect.
cam specs
227/235
.353 .353
.635 .635
110lsa
10% fuel lobe
truck got retuned by local tuner truck runs good to me only issue Im having is idle surges up to 1.1K rpms only with the A/C is on
a/c off truck doesnt surge at all. Even seems to do it when running at high way speeds.
Now I could take it back to the tuner when I have time since truck is my daily driver but wanting to see if I can get some pointers or help If its an easy adjustment.
any help would be great thanks.
Log and current tune uploaded

Marroon GMC Tuned by Palma.hpt
idle surging with AC on.hpl

[GHuggins]

If it's just when your ac is on then either your air models or torque models are wrong and since it doesn't look like your VE was ever touched and your torque model is fairly jacked up I would start there. Adjusting your ac settings may help to cover it up, but you're much better off to correctly calibrate those other items.

[chadtunes]

Hey,

Feel free to correct me. I'm learning how to interpret these logs and looking for trends.

Check out the fuel pressure on your truck vs the others I see. Notice how your fuel pressure is all over the place? I don't actually know what the significance of this is but it's different than the others.



Yours...
Screenshot 2024-09-12 145317.gif

My truck
Screenshot 2024-09-12 145408.png

A log I grabbed this morning.
Screenshot 2024-09-12 145346.gif

[GHuggins]

That's either the hpt scanner issue or a check valve problem. Then if it has an incorrectly set up stand alone regulator system then it's also possibly plumbed wrong, but I would say the scanner issue

I'm actually currently fixing this same issue on another one and it was just the torque models being way off on it. You can tell when the ac engages and timing nose dives and the throttle opens up. Usually a good indicator of things being off.

Now all of this isn't to say that he doesn't actually have a voltage feed issue to his pump that is greatly impacted by the ac being engaged. Hard to say with that log and lack of engine idling with no ac logs. What I can see is the torque model is messed up and the VE isn't dialed in.