Fuel Pressure Test
NOTE:
For additional information on fuel pressure and fuel pump testing procedures, see appropriate NO TROUBLE CODE (NTC) TEST and NO START (NS) TEST in the TESTS W/CODES - 2.4L
article.
CAUTION:
When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See the COMPUTER RELEARN PROCEDURES
article in the GENERAL INFORMATION section before disconnecting battery.
- Disconnect negative battery cable. Release fuel pressure. See FUEL PRESSURE RELEASE under FUEL SYSTEM.
- Using fuel pressure gauge hose, connect Fuel Pressure Gauge (C-4799-B) to fuel pressure test port on fuel rail.
- Connect scan tool to Data Link Connector (DLC), located below driver's side of instrument panel. See Fig 1 . Turn ignition on. Using scan tool, actuate ASD fuel system test to activate fuel pump and pressurize fuel system. Note fuel pressure. Fuel pressure should be 49 psi (338 kPa). If no fuel pressure exists, fuel pump relay and control circuit may be defective. See FUEL PUMP RELAY under FUEL SYSTEM.
- If fuel pressure is less than specified, go to step 5). If fuel pressure exceeds specs, check for kinked/restricted fuel return line from fuel filter to fuel pump module. Fuel filter located on top of fuel tank, near fuel pump module on top of fuel tank. See Fig 2 . If fuel return line is not kinked/restricted, replace fuel pressure regulator. Fuel pressure regulator mounted inside fuel tank, on fuel pump module. See the REMOVE/INSTALL/OVERHAUL - 2.4L article.
- If fuel pressure is less than specified, release fuel pressure. Install Adapter (6631) and fuel pressure gauge between fuel filter outlet line and chassis fuel supply line. Fuel filter is located on top of fuel tank, near fuel pump module on top of fuel tank. See Fig 2 . Turn ignition on. Using scan tool, actuate ASD fuel system test. Note fuel pressure.
- If fuel pressure is now within specification, check for kinked or restricted chassis fuel supply line. If fuel pressure is still less than specified, go to next step.
- Release fuel pressure. Remove fuel pressure gauge and adapter from between fuel filter outlet line and chassis fuel supply line. Reconnect chassis fuel supply line to fuel filter. Install adapter and fuel pressure gauge between fuel pump module and fuel supply line to fuel filter. See Fig 2 .
- Turn ignition on. Using scan tool, actuate ASD fuel system test. Note fuel pressure. If fuel pressure is within specification, replace fuel filter along with fuel lines. Fuel lines are permanently attached to fuel filter. If fuel pressure is still less than specified, go to next step.
- Release fuel pressure. Check for restriction in fuel supply line between fuel pump module and fuel filter. If restriction exists, replace fuel filter along with fuel lines. Fuel lines are permanently attached to fuel filter.
- If no restriction exists, check for restricted fuel pump inlet strainer. Fuel pump inlet strainer located inside fuel tank, on bottom of fuel pump module. See REMOVE/INSTALL/OVERHAUL - 2.4L article for removal procedures of fuel pump module.
- If fuel pump inlet strainer is restricted, replace fuel pump inlet strainer. If fuel pump inlet strainer is not restricted, fuel pressure regulator or fuel pump are defective. Fuel pressure regulator and fuel pump are mounted inside fuel tank, on the fuel pump module. See the REMOVE/INSTALL/OVERHAUL - 2.4L article. Release fuel pressure. Remove test equipment.