LS stalls when AC turns on

[72Z/28]

Originally Posted by aany001

Wondering if anybody has come across this issue. Did an LS swap on my 69 camaro and when I kick the Vintage Air AC on the idle doesn’t bump up and it stalls. Any tips that can remedy this would be greatly appreciated.
Thanks
Steve

Steve please let us know once you fix this issue.
I am having exact set up as yours with OEM PCM and Cammed LS6.
The engine stalls and dies if I rev it when the vintage air AC is on. This happens when the AC clutch is engaged.

The rpm drops below the desired rpm and stalls. In fact, sometimes when letting off the throttle and pressing the clutch to come to a stop, the rpm drops and engine dies even before coming to a dead stop

[aany001]

Originally Posted by 72Z/28

Steve please let us know once you fix this issue.
I am having exact set up as yours with OEM PCM and Cammed LS6.
The engine stalls and dies if I rev it when the vintage air AC is on. This happens when the AC clutch is engaged.

The rpm drops below the desired rpm and stalls. In fact, sometimes when letting off the throttle and pressing the clutch to come to a stop, the rpm drops and engine dies even before coming to a dead stop

Yes for sure I will post my results. So far I have swapped out my corvette alternator for a 2008 I believe Chevy equinox 140 amp alternator but haven’t checked my IAC counts as my scanner won’t do that. Gonna pick up a new scanner and see what happens. I will post my results soon. Thanks everyone
🍻

[camcojb]

Originally Posted by 72Z/28

Steve please let us know once you fix this issue.
I am having exact set up as yours with OEM PCM and Cammed LS6.
The engine stalls and dies if I rev it when the vintage air AC is on. This happens when the AC clutch is engaged.

The rpm drops below the desired rpm and stalls. In fact, sometimes when letting off the throttle and pressing the clutch to come to a stop, the rpm drops and engine dies even before coming to a dead stop

If the IAC settings and base idle screw are adjusted correctly I would look at the Throttle follower tables. I've had this issue myself and adjusting the throttle follower tables allowed me to slow down the rate the throttle drops and eliminate the overshoot on a snap closing of the throttle blades.

[72Z/28]

Originally Posted by camcojb

If the IAC settings and base idle screw are adjusted correctly I would look at the Throttle follower tables. I've had this issue myself and adjusting the throttle follower tables allowed me to slow down the rate the throttle drops and eliminate the overshoot on a snap closing of the throttle blades.

Thanks Jody for the input.

My IAC counts at operating temperature are around 59 or so. I have read the recommended counts for cammed engines should be between 40-60, so I am within range I guess.

I have looked at the throttle follower decay/ delay rates, and the column axis was for vehicle speed not rpm.

So I was not sure what needs to be adjusted. Because the issue I am having is at idle and while driving.

I have seen some videos in youtube where they recommend to increase the timing from 0 to 400 rpm at spark tables( in park & drive) to be at 30 degrees as this would work as stall saver.

I have just changed the timing but need to write the changes into my pcm and see how it goes

[hwyix]

Did you ever resolve this?

What scanner/software package are you using?

I have a 72 el camino with a 2002 5.3L from a chevy Silverado. It has a 1998 camaro cam and intake manifold with 2002 LS6 camaro injectors. It sometimes stalls when coming to a stop.

thanks

[aany001]

I’m still struggling with it. My IAC counts are up around 130 at idle warm. ☹️☹️

[camcojb]

What computer is it and what tuning software are you using?

[aany001]

I’m using the stock 2000 camaro red and blue plug computer. Tuning software I have no idea. I had the car tuned on the Dyno by a shop near me.