So... now that I have a workshop manual I have started
tinkering with the few bits that don't work on my new (?)
1981 vette. First up, cold start is awful. Have a look
around, discover choke butterflies don't close. Look further, discover previous owner has rotated electric choke thermostat clockwise 90 degrees, preventing choke from closing. Re position, and choke closes perfectly !
... but after starting car (much more easily) choke doesn't gradually open like it oughta. Bench test electric choke, it only draws 5 milliamps, and after 15 mins it hasn't budged. I am guessing that this is a bad thing ? All helpful hints appreciated !

With 12 volts DC applied it should be fully open within 15 minutes. You should see movement within a couple of minutes. Its possible that the choke has burned open, but I would be inclined to think the choke has lost its ground first. Try connecting a temporary jumper to the choke when you apply the 12 volts to it and see if it will move.

Yo Eddie, thanks for your reply.
More details for you... I have removed electric choke
cover plate off carb ( 3 screws, plastic cover plate
has metal plate and coil spring mounted on the inside
of it) and powered it +12V to the connection terminal,
ground to the metal plate above which the coil spring
sits, using good old alligator clips and a spare
battery. This is the test scenario where I get 5mA
current flow showing on my multi meter, and no
discernable movement of the coil spring. I was sort of
expecting some form of movement (eventually) with the
coil spring - or am I off base here ??? Chris.

When you have 12 volts the the coil, the most common problem is the coil cover loses it ground to the carb body.

Use a test light or meter to check for power.  If it's there look at the two rivits on the front of the choke cover.  These are the connectors for the heater in the coil.  If they both have power, the ground is lost.  The grounded side should be a 0 volts.

If you have good electrical contacts, and the coil won't move, the choke coil/cover is bad.  But keep in mind this is installed on the carb.

When you have the cover out of the carb, there is no air chamber.  The heater element will heat, but will disapate the heat into the air, and won't warm up the coil.  The metal plate under the coil contains the heater.  It's just a simple 12 volt heater, similar to a toaster element that get hot with current applied.   You can feel if the metal section is creating heat with it out of the car, but you can't expect the coil to move.

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