I'm getting black smoke on start up and a very ruff idle. But only on the first start of the day. And my secondaries still open 1 out of 14 times I floor it. Might it be the choke ? If so is there some sort of adjustment or is a new unit the only way to go ? Max
sounds like possibly two choke problems to me. one would be the primary divorced choke may be sticking shut, causing the mixture to be too rich and giving the black smoke. and, your secondaries could be held shut by the same type of problem, as they have their own choke pulloff at the front of the carb.
Are we talking about a Q-jet? If so there is a vacuum break on the passenger side front of the carb that opens the choke a set amount after the motor starts cold. This leans the mixture somewhat so the engine will run without loading up. This same vacuum break controls the opening of the secondary air valves. If the vacuum break is defective, the car will run very rich when the choke is on and there will be a bog when you nail it when warmed up. Check with the engine running whether the vacuum break is pulling in the choke and air valve linkage. Hope that's clear.
