Holley 6500 2 Barrel

Carburetor:

Carburetor:

This carburetor is used with the Ford Feedback Electronic Engine Control System. It is basically the same as the Motorcraft Model 5200 with an externally variable auxiliary fuel metering system in place of the enrichment valve. The auxiliary system consists of a metering valve assembly, metering valve operating piston and a diaphragm.

The feedback metering valve supplements fuel entering the main well through the conventional metering jet and channel.
- The amount of fuel entering the main well through the metering valve depends on the position of the tapered metering rod in the orifice, Fig. 3. The position of the metering rod depends on the operation of the metering rod piston assembly.

Control vacuum from the vacuum regulator solenoid is transmitted to the cavity above the metering rod diaphragm. When no vacuum is present, the valve spring causes the valve to move to the lowest (richest) position and maximum fuel can pass through the orifice.

As vacuum is applied to the diaphragm, spring pressure is overcome and the metering rod rises, reducing the orifice area and less fuel passes through the orifice.

The metering valve is calibrated so the maximum vacuum signal supplied by the vacuum regulator solenoid raises the rod to the highest (leanest) position.