we just put a LS1 hot cam in a 99 siverado 5.3. it runs fine but wont idle. if you keep your foot on the pedal it is fine but as soon as you let off it dies. any ideas? no aparent vacum leaks

 

Sounds like some tuning is in order...

 

I thought it would run on the factory tune, I guess not

 

no, you will need a retune. mine did the same thing with my new cam

 

dont feel bad i made this same thread about a month ago lol

 

hows the driveability with a stock tune and that hotcam? I had a friend that drove a stock tune trans am around after a magic stick install and it would buck like a wild horse when he would roll through a parking lot in first gear.

 

The reason it's dying is because there's way too much fuel at idle for that cam. To idle properly you need to pull back anywhere from 20-40% of the stock fueling.

 

the desired airflow in gear and desired airflow in park/neutral needs to be raised as well

 

Yep, definitely true as well.

 

That cam will also want a little more timing at idle.