2004 Chevrolet Silverado 5.3L Idle Issues with Both Tunes

[jcmeadows]

To get the obvious questions out of the way; I have the most up-to-date firmware on the T-1000 I just purchased. I am an applications developer by trade so the install/update process is very straightforward. My issue is when I've installed both the Diablo tune and the 87 Octane tune my truck is falling on it's face when I shift from P to R or D and also when the A/C is turned on. The engine dies if I'm in D idling and the A/C comes on and even died when I let off the accelerator to make a turn. I've tried bumping the idle RPMs in all four sets on both tune versions and the idle will come up eventually if it doesn't die first. When the RPMs are bumped like this it still bogs down and sputters when putting the truck in R or D. Am I missing something? Is there a way to remedy this? 2004 5.3L Silverado LS Auto Transmission. No aftermarket mods with exception to true dual exhaust all the way back.

[mikel]

I have randomly seen this behavior on some early GM trucks and it always leads to the alternator being bad, I would check that first...

[jcmeadows]

I re-installed the Diablo Tune this morning after reading a few articles about throttle body issues and TPS replacements. Turns out all I needed to do was run the truck long enough for it to reach it's normal operating temperature and let the ECM relearn/adjust the idle itself (20-30mins tops); works great now. Thanks for the quick response, I drove the truck using the monitoring feature on the T1000 and the voltage holds right where it's supposed to.

[mikel]

glad to hear it.