Troubleshooting Diagnosis - Generic TR 125 Service Manual

16.2.10.3 Fuel pumps fault diagnosis:
1. After the key is turned on, the pump will operate for about 3 seconds or so; if you can hear the pump
running, please go directly to 4:
2. Disconnect the pump connector, detect whether the supply voltage of the pump is about 12V;
3. If there is no problem for step 2, make external connection to battery to provide 12V DC to test whether the
pump is operating well.
4. If the pump is operating normally, use petrol pressure gauge to test the tubing pressure of the front-end of
engine is about 250Kpa during idling of engine;
5. If the line pressure is lower than 220Kpa, check if there is leakage for the oil pipeline, if oil pump is inverted,
or if there is blockage for filter.
16.2.10.4 Common problems for fuel pump:
1. The fuel pump assembly plug is reversed, resulting in the reversal of the fuel pump, so it cannot provide
sufficient fuel pressure to the engine, causing the engine does not work.
2. Pump cannot rotate because of damage.
16.2.10.5 Notes for use of fuel pump:
1. There is no petrol in the fuel tank for the new enginecycle at the beginning, and there is much air in the fuel
oil pipeline after the petrol is filled, so it needs to move the engine for a lot to let the air out completely and the
engine can work properly; this is normal; being unable to start for a long time will not appear in the following
start-up.
2. Because petrol can cool the fuel pump, do not let the pump work with little oil or no oil; otherwise it will
burn the fuel pump.

16.3 Troubleshooting diagnosis

Fault light is located on the dashboard with a FI mark below. Under normal circumstances, open the key, the
fault light will be on, which means that the EFI system is in power state and can work; the fault light are not on,
which said EFI circuit is out of power supply, and will not work, and it needs to check the fuse and the battery
positive and negative connections. After the engine is started, the fault light is off, which means there is no
fault; conversely, if the engine is started the fault light is still on for long, which said the EFI system is not
working properly, and there is a failure needing to troubleshoot.
At present there are three ways to detect fault:
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