Fuel Pressure
- Disconnect fuel pump relay. See FUEL PUMP RELAY LOCATIONS
table. Start engine (if possible) and allow to die. Connect pressure gauge to fuel line at fuel filter. Reconnect fuel pump relay.
- Turn ignition on. Jump engine compartment test connector terminals F/P and GND. If pump does not run, check fuel pump circuit and fuel pump relay. See FUEL PUMP CIRCUIT & RELAY below. Start engine. Check fuel pressure with vacuum connected to and disconnected from pressure regulator. See REGULATED FUEL PRESSURE
table. Turn engine off.
- Operate fuel pump for 10 seconds. Turn ignition off. Wait 5 minutes. If residual pressure is at least 21 psi (1.5 kg/cm2
), go to next step. If residual pressure is not at least 21 psi (1.5 kg/cm2
), perform fuel pump maximum pressure test. See next step. Wait 5 minutes and ensure residual pressure is at least 50 psi (3.5 kg/cm2
).
- Check fuel pump maximum pressure. Plug fuel pressure gauge outlet. Operate fuel pump. DO NOT
operate longer than necessary to check pressure. See FUEL PUMP MAXIMUM PRESSURE
table.
- Turn ignition off and disconnect jumper wire at fuel pump check connector. If pump does not meet specifications, check fuel pump circuits, fuel pump, fuel tank and fuel filter. Repair or replace as necessary.
FUEL PUMP MAXIMUM PRESSURE
| Application |
Pressure |
| MX-3 |
69-95 psi (4.9-6.7 kg/cm2
) |
REGULATED FUEL PRESSURE
| Model |
@ Idle W/Vacuum psi (kg/cm2
) |
@ Idle W/O Vacuum psi (kg/cm2
) |
| MX-3 |
27-37 (2.0-2.6) |
|