hello everyone. i have a 1984 Z28. its got 196k on a 305. the car runs great, but over the last 2 weeks the rpm's are revving too high. the normal it usually revs at is around 8 or 900, it is at 1500 to 2000 rpm's. is this normal? is it because of the colder weather? its also a 4 barrel carb and has never seen winter. any help would be greatly appreciated!

 

It's probally sticking on high idle.
After it warms up for 5-10 min Blip the throtle and it (should) idle down.

 

camarov, welcome aboard thirdgen.org.

Sounds like your choke isn't opening up, or as zipfast said, the fast idle isn't releasing (choke not opening will keep the fast idle from releasing). #1 cause of choke not opening is the power wire that heats up the choke thermostat coil isn't connected or doesn't have power. After that comes gummed up linkage, and worn out choke thermostat coil.

Try this test: With the engine cold and not running, remove the air cleaner (this is the time to check if the choke wire is hooked up - if it isn't, hook it back up and forget this test). Observe the position of the choke butterfly. Now, open the throttle, what does the choke do? It should snap closed. Now, start the engine, and watch the choke butterfly. It should slightly open as the vacuum break (aka, "choke pull-off) pulls in and lets a little more air through. Let it keep running, open the throttle a little every half minute or so. The choke should continue opening gradually, and the idle speed drop. If it open within 5 minutes, you either have a power problem to the choke, a bad choke thermostat, or gummed up works.

Also, refer to the information in this sticky in the top section of this forum: https://www.thirdgen.org/forums/carb...e-rebuild.html
It has a wealth of information, referred to it myself last night as I was adjusting the carb on Camaro #2.