Fuel Pressure
- Ensure battery is fully charged. Turn ignition off. Disconnect negative battery cable. Go to step 3.
- Disconnect vacuum pipe from rear of air intake chamber (to access fuel hose). Cover fuel inlet hose banjo bolt (at fuel rail) with shop towel. Slowly loosen banjo bolt to relieve fuel pressure. Remove banjo bolt and gaskets. Go to step 5).
- Install Fuel Pressure Gauge (SST 09268-45012), gaskets and banjo bolt. Tighten banjo bolt. Reconnect negative battery cable. Connect scan tester to Data Link Connector (DLC) No. 3. See Figure.
- Using scan tester manufacturer's instructions, activate electric fuel pump and note fuel pressure. Fuel pressure should be within specification. See FUEL PUMP PERFORMANCE table.
NOTE:
Fuel pump may also be activated by connecting battery voltage to specified terminals on fuel pump. See Figure. FUEL PUMP PERFORMANCE
| Application Type Tested |
At Idle W/Vacuum psi (kg/cm2
) |
At Idle W/O Vacuum psi (kg/cm2
) |
| Fuel Pump |
28-34 (2.0-2.4) |
38-44 (2.7-3.1) |
- If fuel pressure exceeds specification, replace fuel pressure regulator. If fuel pressure is less than specified, check for defective fuel lines, connections, fuel pump, fuel filter, fuel pressure regulator or fuel pressure control Vacuum Switching Valve (VSV, if equipped.
- Remove scan tester from DLC No. 3. Start engine and allow to idle. Disconnect and plug vacuum line at fuel pressure regulator. Note fuel pressure. Reconnect vacuum hose on fuel pressure regulator and note fuel pressure. Fuel pressure should be within specification. See FUEL PUMP PERFORMANCE table.
- If fuel pressure is not within specification, check for defective vacuum hose or fuel pressure regulator. Shut engine off and note fuel pressure. Fuel pressure should hold at least 21 psi (1.5 kg/cm2
) for a minimum of 5 minutes. If fuel pressure does not hold as specified, check for defective fuel pump, fuel injector or fuel pressure regulator.
- Disconnect negative battery cable. Remove fuel pressure gauge. Reinstall banjo bolt using NEW gaskets. Tighten banjo bolt. Install negative battery cable.