Fuel pump

Examination

Turn on the ignition and listen to the operation of the fuel pump (the sound of a running electric motor should be heard from under the rear seat). Each time the ignition is turned on, the pump should turn on for 1-2 seconds. If the pump turns on and runs constantly, then the ECU may be faulty and the car must be taken to the MOT station for a complete check of the fuel system.

Check the operation of the fuel pressure regulator, which is determined by the pulsations of fuel in the regulator and the supply hose from the fuel filter.

If the pump does not run, check the fuse, relay and wiring. Also check that the fuel pump circuit breaker is on.

Fuel pressure control

A pressure gauge must be used that connects to the fuel line between the fuel filter and the fuel line. On Zetec and Zetec-E engines, a pressure gauge with an adapter must be used so that it can be connected to the valve on the fuel line (closed with a blue plastic head and located at the junction of the fuel supply pipe and the fuel line). With the special tool FORD 29-033, a conventional pressure gauge can be used.

When using a special tool, check that the plug is turned counterclockwise as far as it will go. Connect the pressure gauge valve according to the manufacturer's instructions (see fig. 4D.10).



Start the engine. After stabilizing the pressure in the fuel system, take readings from the pressure measuring device and compare it with the required readings:

• if the pressure is higher than normal, then check the capacity of the return fuel line. If the fuel line is normal, replace the fuel pressure regulator.
• if the pressure is below normal, then check the condition of the fuel supply hose, fuel pump and fuel filter.

Disconnect the vacuum hose from the pressure regulator. The pressure indicated by the meter should increase. If there is no increase in pressure, check the condition of the vacuum hose and fuel pressure regulator.

Reconnect the vacuum hose to the regulator and turn off the engine. Check the pressure in the fuel system 5 minutes after turning off the engine. Disconnect the fuel pressure gauge from the line. Start the engine and check the fuel system for leaks.