when i start my car, the idle will stay normal, but after letting it run for a little, or driving around, my idle will start to jump around, then get real low, making my whole dash shake. im a n00b so PLEASE HELP!!

p.s. - i have a 92 LS.

 

IT MIGHT BE A SENSOR THAT SITS BEHINE THE INTAKE MANI......I DONT KNO ITS NAME BUT I HAD THAT SAME PROBLEM........I CHANGED IT N IT IDLE NORMAL

 

I had almost the same problem about a month ago after i had my timming belt replaced.I got a timming light and it was at 13 degrees btdc.I also noticed that they had the top alternator bolt was pushed past the original spot further towards the firewall.After fixing these problems the idle is 99% fixed.It will still drop to around 690-710 rpms every once in a while.Im pretty sure im in need of a valve adjustment and im confident(knock on wood) that will take care of that little 1%.
Hope this helps.

 

Check for vacuum leaks. Check/clean the FITV and the IACV. Purge the cooling system of air.

 

how do i go bout purging the cooling system of air?

just dump out my coolant and replace it?