General Motors — Draining the FCC Bowl (Engine Off)
Maintenance · Fuel Control Cell (FCC)
From a General Motors owner's manual covering: Carb 5.7L, MP 5.0L, MP 5.7L, MP 6.0L. Check it applies to your exact model before use.
Before you start
- Both fuel and water will drain from the FCC bowl.
Procedure
- Disconnect the two-wire electrical connectors from the FCC and the Low Pressure Fuel Pump (LPFP).
- Remove the 7/16 inch plug and drain the bowl contents into an approved container.
- Apply pipe sealant suitable for use with gasoline to the threads of the 7/16 inch plug.
- Tighten the 7/16 inch plug.
- Reconnect the two-wire electrical connectors to the FCC and LPFP.
- Cycle the ignition key several times to run the electric fuel pumps and fill the FCC bowl with fuel; inspect the drain plug area for leaks.
- Start the engine and inspect for fuel leaks.
Source: General Motors owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.