Right, stoopid question time...
Fiddling around under my '80s centre console, i have unearthed a relay, which i have identified from the wiring diagrams as the "choke heater". Very good. Just don't know what it is! I guess the standard set up for this car is an automatic choke - even though I've got an edelbrock carb on there now, it still retains the auto choke. My (limited) experience of auto chokes involves a water jacket from the inlet manifold around a bi-metallic spring attached to the choke butterflies - water temp then determines the twist in the spring and hence the amount of choke. Looking at the edelbrock, the choke's purely electrical, which i guess is where this relay comes in (and the little orange choke light on the tacho). Can anyone explain how this system works? OK, i reckon i could probably work it out by poking around in the carb whilst switching the ignition on and generally faffing around, but i'm sure there's someone out there who could explain this in one sentence! And probably laugh at my ignorance! And I thought i was reasonably clued up.....
Thanks in advance

Don't have a clue. "The Toy" has the base 300hp/350ci with a spring-type setup mounted to the intake manifold at the base of the carb and connected to the choke butterfly. When the engine is cold the spring is tighter which holds the choke more open. As the engine warms up the spring expands which allows the choke to close. All those electronics baffle me which is why I don't do much work, other than basic maintenance, on the other vehicles in the family fleet (all 10 years old or less versus 33 years old).

i believe i remember some carbs having an electric element to heat up the bi-metalic spring rather than using the hot water. this was an emission item as it would allow control of the chocke better and open it up sooner rather than have to wait till the water heated up.

yeah, definitely a new one on me....

my understanding of it is this: turning the key to run, but not starting the motor gives 12 V to the spring, which heats up and twists the choke butterflies.
What i dont get is does the heating carry on after the engine 's started, and if so, how long for? How does the system "know" the engine's warmed up and doesn't need choke anymore? Perhaps the whole thing's timed by the relay i found under the console....

Of course it makes absolutely no difference whether i find this out or not, (unless it decides to go wrong) but it just intrigues me... Someone out there must know!

72's right, the electric heater makes the choke come off sooner. I guess they figured it only takes so many seconds for a cold motor to wean itself off the choke, regardless of the water temp, so they went electric. If the motor is warm, the coil is already relaxed so the heater does nothing. Joe

Nice one, thanks guys.