Hello All,
I have a 6139 Carter Thermoquad on my 318/A-904 combo that's in my '72 Challenger. I've basically cloned the '72 340 fuel system setup: Carter TQ 6139 carb, stock 340 manifold, thick stock-style carb base basket, reproduction '72 model year choke thermostat, reproduction fuel pump to carb fuel lines, along with the stock throttle cable/linkage setup. The carb bowl vent is also plumbed into the charcoal canister. I've had this setup on my 318 for over a year and it runs great when warmed up. However, I continually run into problems with getting it to start cold.
Here's the situation: if my Challenger sits overnight, the engine will fire right up the next morning after pumping the gas pedal 1-2 times as it sets the choke closed. However, if it sits in the garage for more than 2 or 3 days, it's a pain to start cold. At first, I had to pump the gas pedal 3 to 4 times for it to start, but over the winter, it got progressively worse. Pumping it 3-4 times no longer works and leads to a flooded condition instead. What's interesting is that it will start if I leave the choke open and don't pump the gas pedal at all...it catches and then I blip the gas pedal a couple of times to stabilize it and let the fast idle do its thing until the engine is warmed up. So, starting the engine with the choke left open confirms the flooded condition I have.
Question now is: what is causing this? Is it the plastic wells that are glued to the phenolic bowl going bad and leaking, bad o-rings, or both? Should I continue to keep the carb bowl vent plumbed into the charcoal canister or leave it out "in the open?" Again, once the engine is warmed up, it runs great and I have absolutely NO warm start or hot start issues.
Thanks for the help!