- Power supply is ok.
- Fuel pressure regulator and residual pressure are normal.
- Fuel filter is ok.
The performance of the fuel pump is measured at a pressure of 4 bar. Therefore, before checking the performance, it is necessary to check the pressure in the fuel system.
The amount of fuel that has drained into a measuring vessel during the measurement is measured.
- Turn on the power to the pump for about 5 seconds to prime the fuel filter.
- Empty measuring container.
- The performance of the fuel pump depends on the voltage applied to it. To measure voltage, connect a multimeter to the battery terminals.
- Turn on the pump power for 30 seconds, while measuring the voltage at the battery terminals.
- Compare the measured capacity with the nominal value.
Dependence of the minimum fuel supply on the battery voltage (see fig. VC2.095)
Notes:
*) minimum supply cube. cm in 30 sec.
**) voltage at the fuel pump with the engine stopped and the pump running (about 2 V less battery voltage).
Countdown example
During the test, the voltage at the battery terminals was 12.5 V.
Since the pump voltage is about 2V less than the battery voltage, the minimum flow is 540 cm3 in 30 sec.
If the minimum capacity is not reached, it is necessary to: check the fuel pressure line leading to the filter for pinches, kinks or blockages.
If the fuel line is in order, you need to: measure the performance up to the fuel filter.
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