96 silverado high idle speed
got an annoying problem 5.7vortech
my 96 k1500 z71 silverado is idling at 1500-1700rpm hot or cold. when driving and i slow down for a stop the engine races at 1500+ rpm until i come to a complete stop, then it will idle down to 700rpm. But if i then switch it into park or neutral, the rpm's will increase back up to 1500 before settling back down to 1000rpm. This has been getting steadily worse and now the truck seems to hesitate intermitently while driving in the city, like something is backing off the throttle speed.
things i've done so far....
new cap rotor wires
sprayed the intake from above with ether, no change in idle.
also, there seems to be alot of vacuum coming from the oil fill tube. i have seen blowby before but not a vaccumn of air in the crankcase.
don;t see any black smoke from the tailpipe....so not rich
any ideas at to what's causing this to happen?
it's really getting hard to slow this truck down for stop signs and stuff.