Description

Make sure of fuel leak when fuel pressure gauge is installed for low pressure fuel system. Make sure of fuel leak after reassembling fuel hose quick-connector.

If fuel pressure of low pressure fuel system is low and engine stalls (vehicle is being stopped) although fuel pump is operated and fuel is supplied, Inspect hose leak of fuel pump in the fuel tank.

Diagnostic Procedure
Maximum supply pressure of low pressure fuel pump inspection
1.

IG S/W 'OFF', ENGINE 'OFF'.

2.

Disconnect fuel supply hose quick-connector of fuel filter.

☞ Make sure of fuel leak after disconnecting fuel hose quick-connector and an inrush of foreign substances.

3.

Install low pressure gauge to fuel hose.

☞ Make sure of using low pressure gauge (CRT - 1051).

note

Refer to 'CRT-1000 Tester composition' of detail inspections (Equipment settings).

4.

Operate the fuel pump by turning IG S/W 'ON' or by connecting jump wire directly after removing the fuel pump relay.

☞ Low fuel pressure will be increased within approx 2 seconds after turning IG S/W 'ON'.

5.

Check the low fuel pressure. (Pressure must be increased to relief pressure of the fuel pump.)

■ Specification : Approx. 7.0 ~ 7.5 bar at IG key "ON"

☞ Make sure of fuel leak in the quick-connector at ENGINE 'ON' after installing pressure gauge.

Symptom

Inspection procedure

Case1

● Low fuel pressure is NOT increased to relief pressure of the fuel pump or Low fuel pressure is released rapidly after stopping operation of fuel pump.

● If there is no leak, Inspect fuel hose damage, disconnection of the fuel pump in the fuel tank and block of the pump strainer.

Case2

● Low fuel pressure is increased to relief pressure but rising time of pressure is too slow.

● Go to "Fuel filter inspection" procedure.

Case3

● Fuel pressure is higher than relief pressure (7.5 ~ 8.0 bar) or Low fuel pressure is released rapidly after stopping operation of fuel pump.

● Replace the low pressure fuel pump. (Relief valve in the fuel pump is stuck.)

Яндекс.Метрика