PV in carb
 

What function does the PV valve perform in the carberator ?How does it work? Can it be blocked off with out adverse effects? Tks.

Re: PV in carb
 

The power valve delivers additional fuel at those times that a lack of vaccuum exists at the venturi. This extra fuel is required to balance the fuel/air ratio, and although the Ford name for the part is the "Economizer Valve", it is not to be considered expendable for reasons of fuel economy goals. Your engine would stall if the valve were blocked off, and conversely, would run rough and foul the plugs if its diaphram were to fail.

Re: PV in carb
 

The air fuel ratio needs to be richer at full power operation. When the vacuum drops below a certain value, determined by which power valve you have, the valve opens and allows additional fuel. Without the valve, the engine would be lean at higher power levels. If you block the power valve, you need to install larger jets which will hurt your economy.