Electric Choke not Working???

[Zilverado]

So I've gone through the exercise of adjusting my electric choke on my Q-jet but have problems. I go to start the truck when it's cold (I mean cold - I'm in Canada). It starts and runs good and the choke is open about 1/8" as it should be, right? Idle speed is good.

Well, I can stand there and just watch the choke butterfly move. Within minutes - before anything has warmed up - the choke is completely open. Needless to say, the engine isn't ready for no choke, so she reacts accordingly.

So what's going on here? Is my electric choke not working or what? Is it possible that there is too much voltage in the choke wire, causing it to warm up too fast?

Any suggestions?