What is wrong with 1989 RS 2.8 Camaro if you replaced the fuel pump and it runs for 3 seconds cuts out have no pressure only 6 volts are going to pump?

The problem with your 1989 RS 2.8 Camaro is almost certainly the low voltage reaching the fuel pump. Six volts is far too low to operate the pump properly; it needs the full 12 volts of the car's electrical system. The issue isn't the fuel pump itself (unless it was damaged during installation), but the *power supply* to the pump.

Here's what to investigate:

* Wiring: Check all the wiring between the fuel pump relay, the fuel pump, and the power source (likely the battery, through a fuse). Look for:

* Broken wires: Especially near the tank, where wires are subject to chafing and movement.

* Corroded connections: Clean any terminals or connectors with a wire brush and electrical contact cleaner.

* Loose connections: Ensure all connections are tight and secure.

* Incorrect wiring: Double-check that the fuel pump is wired correctly according to the car's wiring diagram.

* Fuel Pump Relay: The relay is a switching device that controls power to the pump. A faulty relay will only send a partial voltage, or no voltage at all. Test the relay itself (many auto parts stores can test them for free) or replace it.

* In-Tank Fuel Pump Harness: On many fuel-injected cars, the fuel pump sits inside the tank. The wiring harness that connects to the pump can be prone to corrosion, chafing, and damage within the tank. This requires tank removal and inspection for damage.

* Fuse: Check the fuse(s) related to the fuel pump in the fuse box. A blown fuse will also prevent the pump from getting full power.

* Voltage at the Fuel Pump Relay: Use a voltmeter to check the voltage *at the fuel pump relay terminals*. You should see battery voltage (around 12V) on the power side when the ignition is on. If you don't, the problem is likely before the relay.

* Ground Connections: Poor ground connections can cause voltage drops and erratic operation. Ensure that the ground connections to the fuel pump and related components are clean and secure.

Important Safety Note: Before working on the fuel system, disconnect the negative battery cable to prevent sparks and fire hazards. Gasoline is extremely flammable.

In short, the 6 volts indicates a significant problem in the electrical supply *to* the fuel pump, not the pump itself. Start with the simplest checks (fuses and wiring) and work your way to the more involved troubleshooting (relay, in-tank harness). A wiring diagram for your specific year and model Camaro will be very helpful.