* Faulty Fuel Pump Relay: This is the most common cause. The relay is an electromechanical switch; it's possible the contacts are worn, dirty, or stuck. Replacing the relay is a cheap and relatively easy fix.
* Bad Relay Wiring: Check the wiring harness connected to the relay. Look for:
* Broken or corroded wires: Inspect for any damage, especially where wires bend or connect to the relay.
* Loose connections: Ensure all connectors are securely fastened.
* Short circuits: A short circuit can prevent the relay from functioning correctly.
* Open Circuit in the Relay's Control Circuit: The relay doesn't just receive power; it receives a signal telling it to activate. This signal comes from the car's computer (PCM) or other related circuits, likely through a fuse. A break in this signal path would prevent the relay from closing even if the relay itself is good. You'll need a multimeter to check for continuity along this circuit. A wiring diagram for your specific 1987 Corvette is crucial here.
* Faulty Inertia Switch (or Crash Sensor): Some vehicles have an inertia switch that cuts power to the fuel pump in the event of a collision. If this switch has tripped, it needs to be reset (usually a small button on the switch).
* PCM (Powertrain Control Module) Problem: Though less likely, a faulty PCM could be sending the incorrect signal to the relay. This is a more involved diagnosis and often requires professional help.
* Fuel Pump Inertia Switch: This safety switch cuts power to the pump in a crash. Check if this switch has tripped. There's usually a reset button.
Troubleshooting Steps:
1. Visual Inspection: Carefully inspect the fuel pump relay and its wiring for any obvious damage.
2. Relay Replacement: The easiest and cheapest first step is to replace the fuel pump relay with a new one. This is often the solution.
3. Wiring Check: If replacing the relay doesn't fix it, use a multimeter to check the wiring for continuity and voltage at various points in the circuit. A wiring diagram is essential for this step.
4. Check the Inertia Switch: Locate and check the inertia switch. If it's tripped, reset it.
5. Fuse Check: Check the fuses related to the fuel pump circuit.
Remember to disconnect the negative battery terminal before working on any electrical components to prevent accidental shorts or injury. If you're not comfortable working with car electrical systems, it's best to take your Corvette to a qualified mechanic. They have the tools and expertise to properly diagnose the problem.
