Wanting A Little Insight

[whitelion]

so today i drove my truck today, as i do most days, fired it up, shifted to reverse, released my parking brake, moved out of my parking spot, back to drive and pulled away. However, the truck just felt kinda funny in my hands, and sure enough according to the tach it was running about 250-500 rpms faster than usual. upon coming to my first stop light i shifted back to park and then back to drive. sure enough it idled back down to is usual engine speed. Im really not worried, but im extremely curious to know what could have made this happen.

[old-chevy-dude]

sounds like a computer burp in the PCM..

[jro909]

was the motor cold? the computer forces the engine to idle faster and coast a tad faster when its not warmed up enough...i atleast let my truck idle down to 500ish rpms before driving, it gives me peace of mind

[whitelion]

it was cold, but its never idled that high before when it was cold.

[jro909]

when my truck is cold, we will say 45 degrees outside...it will rev up to a tad below 1000 rpms and then drop down to 800 or so for a good 5 minutes and then eventually go down to 500ish rpms when it begins to warm up...if i jump in it and start it and throw it in gear it will still have enough revolutions to propel itself at a nice coasting speed because the motor is cold and trying to warm itself up to be able to use fuel on an effective level...if your truck is idleing high even when the motor is warm then you may have a vacuum leak or something else going on

[KMGZ400]

i think its normal, my 5.3 seems rev up and do diffrent things everytime its cold, like you say yours did

[leg7228]

i think its normal, my 5.3 seems rev up and do diffrent things everytime its cold, like you say yours did

 

 

+1 Same here.