On my 73 340,the choke stays on a long time before it will finally kick down.Its an electric choke.Wondering if it could be a ground problem ,as everything on the block was painted.I also do not have the curb idle solenoid wired in.What exactly would that effect.And does that wire to the alternator?Seems when I first start the car,there is no choke or fast idle at all until it warms up a bit,and then slowly gets to high and difficult to kick down,but does eventually.