This morning i got to start my 99 z71 1500 and battery was dead. I get it started off a jump but it went to 3000 rpm and it idled down to 1500 then back up. What is going on here, I did replace fuel filter a few weeks before. Hope someone can help!

 

Once the battery becomes dead the truck computer must relearn all the factory setting which include monitoring for smog. just drive it a few times with a cold start and driving up to 55+ a few times and hopefully all should be good.

 

Normal.

When the battery voltage is low, the computer kicks that idle up to speed the recharge. Drive it.

Allan