75 Scotsdale carb loading up after warmup.

[Travis.Rathmann@gmail.com]

At my wits end.
Carb seems to load up after warmup. occasionally starts backfiring thru carb.
When this happens the truck stops shifting into 3rd gear.

This is my only means of transportation and I am very low on funds.
Any help would be greatly appreciated.
Auto/350/2wd

[gildardo01]

you can start with the choke see if it opens up completely when its warm... check for vacuum leaks.. such as the lines, the carb/intake gasket you can do this my spraying some carb cleaner at the base of the carb... disconnect the vacuum lines from the carb and plug them up see how it idles then... does your carb have an EGR? weŽll see what over members come up with...   

[gildardo01]

oh and your plugs are going to be pretty dirty since your more than likely running rich in fuel.. instead of buying new plugs right now... you can clean them up with some sand paper 200 grit down to about 320-400... just enough to get the carbon off of them... then recalibrate them and theyŽll last you a few hundred miles... iŽve done it my self...

[bd]

...Carb seems to load up after warmup. occasionally starts backfiring thru carb.
When this happens the truck stops shifting into 3rd gear....  Auto/350/2wd

Please provide a few more details.  Are you hearing a "pop-pop-pop-pop" through the carb with rapid throttle opening (possible flat cam lobe), or just a single backfire (fouled plugs or a lean backfire)? 

A heavy (saturated) carburetor float or high float level setting can cause the engine to run rich when warm - so can a choke that doesn't open properly, as Gildardo suggested - so can leaking fuel passages internal to the carburetor, and so on.  What exactly are the symptoms that make you think the carb is dumping too much fuel? 

Could the engine, in fact, be starving for fuel (plugged fuel filter, fuel pump, fuel line, etc)?