Yeah I was watching some videos on messing with the spark under/overspeed. Is there any real negatives to doing that?

Also I'm not sure why but my Tahoe will not let me write in high speed mode. Every other vehicle I've messed with it was not an issue. I thought I read somewhere it was a low voltage or bad connection problem however I have a brand new AGM battery and I turn all accessories off during the write.

 

On my s10 the idle over speed corrections would pull timing when I would first tip into throttle which would cause it to bog out. Pretty sure it was a tps calibration issue more then anything as my tps reads a bit funky. As for the only writing in high speed I’ve had a few trucks do that. Seemed to be a voltage issue like you said. Maybe verify voltage or check the data logger in vcm scanner to see.

 

I will have to look at the Voltage from the scanner and see if there's an issue. There is some sketchy wiring I need to tidy up still.

an't wait to get V2 PRO so I can read AFR on the scanner with the AC on. The last few weeks its been hotter than a Minneapolis Police station.

 

It affects how the vehicle will idle. Probably don't need to mess with it if you have a stock cam.

 

It has a little 212/218 cam. I played with the idle over and under speed a tad following a YT video it sounds a bit more aggressive and I have seen any negative effects yet. See how it goes tomorrow with regular driving. It idles so smooth at 580 it's crazy. What's considered to low of an idle?

 

Does it have the factory radio and alarm system?

Aftermarket stuff can make it not let you write in high speed mode.

 

Factory alarm but it has an after market radio and what not. I do always turn the radio off when I go to write, as well as the HVAC, head lights, gauge lights and close all doors. Still haven't checked voltage in the scanner but I probably won't mess with it again until I get the MPVI2.

 

I am not a pro tuner but most of the cals I have opened online seem to hit around 800-900 RPM idle even for moderate cams. I am at 700 with the Tick Stage 2 Towing Cam. Most of the cals will soften up the next column or two away from idle but leave the rest alone.

 

my 219/224 in the 5.3 idled just fine ~625

 

Yea I got 214/224 | .571"/.561 in the truck right now. It idles buttery smooth with some character in the exhaust note. I could drop it down lower like what you have with some compromise to the smoothness of the idle.