1. Relay Check: The FP1 fuse likely protects the fuel pump relay, not the pump directly. Even with power at the fuse, a bad relay can prevent the pump from receiving power.
* Locate the fuel pump relay: Consult your Corvette's wiring diagram to find its location (often in the underhood fuse box or a separate relay center).
* Swap the relay: Try swapping the fuel pump relay with a known good relay of the same type (don't just test it with a multimeter; a relay can appear good on a meter but fail under load). See if this resolves the issue. If swapping relays fixes the problem, you've found the culprit.
2. Wiring and Connections: Even with a good fuse and relay, there could be a break in the wiring between the relay and the pump.
* Inspect wiring: Carefully examine the wiring harness leading from the fuel pump relay to the fuel pump itself. Look for any signs of damage, corrosion, or loose connections. Pay close attention to connections near the tank, as they are subject to wear and tear.
* Check the inertia switch: This safety device cuts power to the fuel pump in a collision. Locate it (usually under the dash or in the engine compartment) and make sure it's not tripped. Reset it if it is.
3. Fuel Pump Pressure Test: Even if the pump runs, it might not be producing enough pressure.
* Test fuel pressure: You'll need a fuel pressure gauge (available at auto parts stores) to check the pressure at the fuel rail. Consult your Corvette's service manual for the correct pressure specification. Low pressure indicates a failing pump (despite seemingly running), a clogged fuel filter, or a problem within the fuel system.
4. PCM/ECM Issues (Computer): The Powertrain Control Module (PCM) or Engine Control Module (ECM) controls the fuel pump. A faulty PCM could prevent it from activating even if everything else is working.
* Diagnostic trouble codes (DTCs): A scan tool can retrieve DTCs stored in the PCM. These codes can point directly to the problem. A professional scan tool is recommended for a comprehensive diagnosis.
5. Other Possible Issues (Less Likely):
* Fuel filter: A clogged fuel filter can restrict fuel flow.
* Fuel pump ground: A poor ground connection to the fuel pump can interrupt the circuit.
* Ignition system problems: While you state the pump is "good," if the ignition system isn't functioning correctly, the PCM might be inhibiting fuel pump operation as a safety measure.
Important Notes:
* Safety First: Working with fuel systems requires caution. Disconnect the negative battery cable before starting any electrical work. Gasoline is highly flammable.
* Wiring Diagram: Obtain a wiring diagram specific to your 1992 Corvette. This will be invaluable for tracing wires and identifying components. You can often find these online or in a repair manual.
If you've checked all these points and are still stumped, seeking professional help from a mechanic specializing in Corvettes is advisable. They'll have the specialized tools and expertise to diagnose the problem more accurately.
