Fuel Pressure Check (PFI)
- Relieve fuel pressure as previously described in FUEL PRESSURE RELIEF (PFI). On all models, connect Fuel Pressure Gauge (J-34730-1) to fuel pressure fitting on fuel rail. With gauge installed at fuel rail connector, turn ignition on. With ignition on and engine off, pressure should read within specification. See FUEL PRESSURE (PFI) table. If no fuel pressure is present, go to step 5).
- Start engine. Pressure should drop 3-10 psi (.2-7 kg/cm2 ). Turn ignition off. Pressure should hold. If pressure does not hold, check for leaking injectors or fittings. If injectors or fittings are not leaking, replace pressure regulator.
- If pressure is present but less than specification, check for restricted delivery line or fuel filter. Repair as necessary. If no restriction is evident, apply battery voltage to fuel pump test connector using a 10-amp fused jumper wire. For location of fuel pump test connector, see COMPONENT LOCATIONS in the article SYSTEM/COMPONENT TESTS .
- Gradually pinch off fuel delivery line between gauge and fuel rail. If fuel pressure increase to within specification, replace fuel pressure regulator. If fuel pressure does not increase with line pinched, check for faulty in-tank fuel pump or partial blocked fuel strainer.
- Apply battery voltage to fuel pump test connector using a 10-amp fused jumper wire. For location of fuel pump test connector, see COMPONENT LOCATIONS in the SYSTEM/COMPONENT TESTS article. Observe fuel pressure reading. If fuel pressure is still not present, check wiring between test connector and fuel pump. If wiring is okay, replace fuel pump.
- If fuel pressure is present with voltage applied to test connector, test fuel pump relay and voltage supply to relay. Refer to the appropriate SYSTEM/COMPONENT TESTS article.
FUEL PRESSURE (PFI)
| Application | psi (kg/cm2 ) |
|---|---|
| 2.3L (VIN A & D) | 40-47 (2.8-3.3) |
| 3.1L (VIN T) | 40-47 (2.8-3.3) |
| 3.3L (VIN N) | 40-44 (2.8-3.3) |
| 3.4L (VIN X) | 32-47 (2.3-3.3) |
| 3.8L (VIN C & L) | 40-47 (2.8-3.3) |
| 4.9L (VIN B) | 40-50 (2.8-3.5) |
| 5.0L (VIN F) | 40-47 (2.8-3.3) |
| 5.7L (VIN 8) | 40-47 (2.8-3.3) |