Fuel Pressure: Testing and Inspection

RELEASE FUEL PRESSURE
Before servicing fuel system components, fuel system pressure must be released. To relieve pressure, proceed as follows:
- Remove fuel pump fuse from fuse block.
- Run engine until fuel remaining in lines is consumed. When engine shuts down, engage starter for approximately three seconds to relieve any remaining pressure.
- With ignition off, replace fuel pump fuse.

Fuel Pressure Gauge:

CONNECT FUEL PRESSURE GAUGE
- Connect a fuel pressure gauge to fuel pressure line.
Fuel pressure gauge - Kent-Moore P/N J-35957-1
Fuel rail access fitting - Kent-Moore P/N J-35957-2

VSV Connector Terminals:

- Disconnect the fuel pressure VSV connector.

MEASURE FUEL PRESSURE
Start engine and idle.


- Disconnect fuel pressure regulator vacuum hose and plug.
Fuel pressure should be 294 kPa (42 psi)


- Reconnect hose at regulator.
Fuel pressure should be 245 kPa (35 psi)


- Apply battery voltage to the VSV connector.
Fuel pressure should be 294 kPa (42 psi)
- Disconnect vacuum hose from regulator and plug it.
- Turn engine off and observe pressure reading.
Fuel pressure should remain approximately 245 kPa (35 psi) for four (4) minutes.

INSPECTION AND REPAIR
If fuel pressure did not reach standards, check the following:

Fuel Pump Connector Terminals:

- Apply battery voltage directly to fuel pump connector and re-measure pressure.
a. If fuel pressure reaches normal level:
- Check fuel pump circuit and correct as necessary.
- Check fuel pump relay.
a. If fuel pressure remains unchanged:
- Check for restrictions in fuel delivery circuit.
- Pressure regulator defective, replace.
- Fuel pump malfunctioning, replace.

OPERATING FUEL PUMP WHEN ENGINE DOES NOT RUN
The fuel pump will only operate for two seconds if the engine does not run (no engine rpm signal). The following procedure will by-pass the relay and supply power to the pump.

Fuel Pump Relay:

- Remove fuel pump relay from underhood relay/fuse box.

Fuel Pump Relay Terminals:

- Using a jumper wire, connect relay connector terminals as shown.
- Turn key ON.
Fuel pressure should be 245 kPa (35 psi)