We changed the fuel pump, fuel filter, plugs and wires, fuel tank, air cleaner and so on. The issue is when you start the truck, it starts right up. let it sit idling to warm up and it starts choking out and dies. It is running extremely lean and the carburetor is flooding. It will do the same when going down the road any type of distance and I would have to "two foot" it in order to keep it running. Once it dies, it goes into a hard start. I have to let it cool off and the fuel evaporate from the bowl, then it willl start and run good again for a while. The last thing done was replace the tank. It ran awesome for about a week and then it just dies...I have not been able to drive it any distance at all. replaced the distributor cap and rotor button and the pcv valve. I did have a mechanic tell me that it would be a good idea to either rebuild or replace the carb but I am not sold on the Weber. I am pretty confident that the carburetor is the issue. However, I am open to any suggestions on where to go from here. Just so you know, .I have removed and disassembled the carburetor to start the rebuild. Just wanting to get some info before I continue.
So, thank you for your interest and any help and or suggestions will be greatly appreciated.
Flooding and lean running do not usually go together; flooding is almost by definition an extreme rich condition.
If the carb is flooding, usually that is a float or float needle valve problem. Replace the float needle (and needle seat if possible). These parts usually come in a re-build kit.
Sometimes (rarely), the actual float can leak and the float will fill with gas and not "float" any more. This would be obvious when you disassemble the carb; take out the float and shake it - you should not feel any fluid moving inside of it. Replace it if there's any doubt. Not an expensive part (if it's still available).
Once you have eliminated those possibilities, check the float level. You can adjust the float level by slightly bending the (usually brass) hinge arm. There should be a spec for setting the float level in the factory service manual.
If your carb has an electronic choke, check it to make sure it is opening after warm-up.
If the carb is running lean, that is either a fuel delivery problem, a vacuum leak (both common) or a jetting problem. You have addressed the fuel delivery by replacing the fuelp pump, filter, and gas tank. The one remaining thing to do is to blow-out the fuel lines with compressed air. If there was crud in the old tank or filter, there is almost certainly crud in the fuel lines also.
Check for vacuum leaks (usually at the base of the carb where it mounts or where the intake manifold mounts on the head) by spraying carb cleaner or even WD-40 on those areas while the engine is running and idling. A change in rpm will indicate a leak.
Jets (particularly small pilot and idle jets) can become clogged from using ethanol-blend gasoline. Usually this will be obvious as a white encrustation or blockage of the jet orifice. If the jets are blocked or obstructed, you may be able to clean the white corrosion out carefully with a small drill bit. Be careful not to drill the orifice larger. It's also possible (but not likely?) that a previous owner changed the jets to the wrong size(s).
In my experience, Aisin carbs are very good; if it were mine, I would not replace it with a Weber. Weber carbs were popular (allegedly) high-performance upgrades for VW beetles and some other cars when I was young, but I don't think they or any other aftermarket carb are a panacea for all ills.
Good luck with your diagnosis and fix.