FC is a switch inside the N/A's VAF. It's an emergency fuel cut out. If the flap in the meter closes while the ignition is on the fuel pump will loose power. So, if the meter is unplugged or the air flow meter is not connected to the intake no fuel pump. To test the FC switch you just need to test pins 1 and 2 on the AFM for continuity when you manually move the flap and ∞ when the flap is closed.
MK3 TSRM On-Line
Have you checked for error codes?
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