Damn Thermoquads.

I have a real crappy run of luck with these carburetors.
Every one that I have owned, old or rebuilt seem to give me trouble. The latest is the one in my 73 Dart Sport. It is an original 340 car that I got without an engine. I had a low mile 360 on a stand so I regasketed it and put it in.
The car can sit overnight and be impossible to start. No action from the accelerator pump. The fuel filter has gas clearly visible. I can spritz a quick shot of ether, carb cleaner or even brake cleaner and hit the key and it will start right up and idle fine. I can let it run a minute or so and the accelerator pump works great. An hour later, it starts fine. The next day, it requires another spray of something to start.
This dude runs great! It idles great, sounds nice and smooth. It makes plenty of power with no bogging or hesitation. It just fails to start when cold. I plan to sell this car so I really need it to run right.
This carburetor has been rebuilt by a local guy that I trust. I even took it back once and he got it to work while on the work bench. I am tempted to just buy a new Street Demon based on the ThermoQuad pattern but I'd rather not spend more money on the car.
Anyone have any tips on these carburetors?