Checking Fuel Pressure
- Relieve fuel pressure. On 2.0L and 2.0L Turbo, remove throttle body bracket. On all models, wrap fuel line with shop towel and disconnect high pressure fuel line at fuel rail. Install Adapters (MD998709 and MD998742) between fuel rail and high pressure fuel line. Connect fuel pump pressure gauge.
- Connect negative battery cable. Apply battery voltage to fuel pump check terminal to activate fuel pump. See Fig 1. Check for fuel leaks. Disconnect battery voltage from check terminal. Start engine and let idle.
- Measure fuel pressure with fuel pressure regulator vacuum hose disconnected and plugged. Measure fuel pressure with fuel pressure regulator vacuum hose connected. See FUEL PRESSURE SPECIFICATIONS table.
- Increase engine speed to 2500-3000 RPM 2-3 times. Ensure fuel pressure does not drop when engine returns to idle. Check for fuel pressure in fuel return hose by gently pinching hose (with hand) while raising engine speed. There will not be any fuel pressure in return hose if fuel volume is low.
- If fuel pressure is too low during test, check for clogged fuel filter, faulty fuel pressure regulator or faulty fuel pump. If fuel pressure is too high, check for bent or clogged fuel return hose or faulty fuel pressure regulator.
- If fuel pressure is the same when fuel pressure regulator vacuum hose is connected and disconnected, check for clogged or broken fuel pressure regulator vacuum hose or faulty fuel pressure regulator.
- Stop engine and check for change in fuel pressure. Fuel pressure should not drop. If fuel pressure drops slowly after engine is stopped, replace fuel pump. When disconnecting fuel pressure gauge, cover hose connection with towel to prevent splash of fuel, caused by residual pressure in fuel line.
- When fuel pressure check is completed, remove fuel pressure gauge and adaptors. Install new "O" ring on end of high pressure fuel line. Connect high pressure fuel line to fuel rail. On 2.0L and 2.0L Turbo, install throttle body bracket. On all models, check for fuel leaks.FUEL PRESSURE SPECIFICATIONS
Application psi (kg/cm2 ) 1.8L & 2.0L W/Vacuum Hose Connected 38 (2.7) W/Vacuum Hose Disconnected 47-50 (3.3-3.5) 2.0L Turbo Manual Transmission W/Vacuum Hose Connected 27 (1.9) W/Vacuum Hose Disconnected 36-38 (2.5-2.7) Automatic Transmission W/Vacuum Hose Connected 33 (2.3) W/Vacuum Hose Disconnected 41-46 (2.9-3.2)