Aftermarket electric chokes, run as-is, are a compromise at best. You set the choke where the engine starts and runs well, and the darn thing is wide open in about 1 minute. You set the choke rich enough that it stays closed for a decent amount of time, and the engine runs so rich at first that you've killed the spark plugs.
I'm speaking of the Holley electric chokes, and I'm assuming yours is similar.
The electric choke has no idea how hot or cold your engine is. You put 12 volts on it and it opens. If the ambient air is colder, it'll open a little slower, but still...
Here's what I did, and it works fairly well. First, set the choke to the point the engine starts and runs well, no chugging, no spitting back. Don't worry about the fact that the choke will open too soon. Find the happy spot where the engine is happy when first started, leave it there, then set the fast idle to match it.
Next, you're gonna have to slow the opening of the choke, if yours is anything like the Holley units I've worked with. I added a 20 watt power resistor (availabe at any decent electronics store) in series with the choke heater to slow the opening of the choke. I think I have a 27 ohm resistor in mine now, and my choke heater is around 10 ohms IIRC. I actually experimented with with various resistors on the bench and timed the choke opening and recorded it in my notebook, which is at my shop now and not at home. I'll be happy to post the data later if anyone wants it. You play with different resistor values to tailor the choke opening time to what your engine is happy with. Lower resistance = faster choke opening. Higher resistance = slower choke opening.
OK, so we've set the choke where the engine starts and runs well, and we've slowed the choke opening with a resistor. Only one problem left to address. You turn the engine off, and the choke closes before the engine cools off, b/c the choke is divorced from the engine. You then start the engine and it runs rich for a long time b/c we added a darn resistor to slow the choke opening!
If your engine has any provisions for the hot air tube, you obviously should connect that to your choke. Mine didn't, so...
You add a thermostatic switch something like this
http://cgi.ebay.com/12-Temperature-N-O-C...id=p3286.c0.m14and put your resistor in parallel with it. This way, when the engine is cold, the switch is open, and power flows through your new resistor. When the engine is hot, the switch closes, the resistor is bypassed, and full voltage is applied to the choke, allowing it to open fast. Chrysler used a similar switch and resistor setup on some of their electric chokes in the 70's. It looked like this
http://cgi.ebay.com/ebaymotors/NOS-Mopar...emZ150291925912If you decide to use one of the cheapie eBay-type themperature switches, you can mount it on a piece of sheetmetal and screw it down under an intake manifold bolt like the factory did with the above unit.
I know this sounds like a lot of work just to get the choke to function well, but believe me, I've been through it and if I could have found an easier way to make mine work well, I'd have done it. I used a wideband O2 meter to lean out the very rich part-throttle cruise condition that all Holleys seem to plagued with then, as expected, the engine became very cold natured, making proper choke operation quite important. I was forced to make my choke work.
DISCLAIMER: The above solution worked for me. Your mileage may vary.
Good luck.
Jim