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Vacuum issues / running rich?

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Fuel Pump has three (3) sources for voltage.
1. Starter Relay during ENGINE CRANK (Battery voltage).
2. Fuel Pump Relay during KEY ON (2-3 seconds)/ENGINE RUNNING (Battery voltage - Ballast Resistor voltage drop).
3. Wide Open Throttle (WOT) (Battery voltage).


O2 Heater Relay serves two (2) purposes.
1. When relay is de-energized (OFF), O2 Heater circuit is ON. KEY ON voltage is supplied for 2-3 seconds since its being fed (B+) by the Fuel Pump Relay (engine fuel prime/heater ON). ENGINE RUNNING voltage is fed by the Fuel Pump Relay all the time (fuel pump running w/ballast voltage drop & heater ON).
2. During WOT, O2 Heater Relay is energized (ON) and voltage is supplied directly to the fuel pump, by passing the Ballast Resistor.

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