I have a third gen like all of you, but where I live it gets cold and snows massive amounts. So I decided to prep my 1/2 ton GMC for the winter. I knew the carb was shot so I replaced it with a rochester 4 barrel with an electric choke. Problem was it stays on fast idle sometimes, when I start it the next day (same temp) it will have no fast idle to warm it up, and I have to feather the gas to keep it running. When it is warmed, it sounds healthy. I blocked off all the proper spots, cleaned and checked the floats before I installed it and took out the old tired electric choke and dropped in a new one. Any ideas? Anybody ?
Thanks in advance

 

Check the vacuum pots on the side of the carb
to see if the diaghrams are shot.
(choke pull off and secondary delay)
Pull the hose off and depress the linkage while blocking the vacuum hole with your finger, then let go the linkage, if it returns out
the diaghram is shot. They both have to work.
There is an anti-stall, anti-run on solenoid
on the throttle linkage. Check to see if it energizers when you turn the key on.
The plunger should move out when U touch the gas. Make sure the is 12 volts going to the electric choke with the key on.