What are the symptoms of insufficient fuel pressure?

[VanMorgan]

The symptoms of insufficient fuel pressure include: insufficient driving power, lack of acceleration power, and engine stalling. Insufficient fuel pressure is mostly caused by a faulty fuel pump. When this occurs, the fuel pump needs to be replaced. To test whether the fuel pump pressure is sufficient: 1. Turn on the ignition switch without starting the engine, and you should hear the fuel pump working for 1 to 2 seconds; 2. Remove the fuel pump relay and use a dedicated jumper wire to connect the fuel pump circuit, then turn on the ignition switch; 3. Connect a fuel pressure gauge to see if the engine can establish a fuel pressure of around 250KPa, and whether the pressure builds up quickly. If the pressure can be established normally, the fuel pump is functioning. Then, turn off the engine ignition switch and observe whether the fuel pressure drops quickly, which helps determine if the fuel pump's pressure relief valve is working properly; 4. Connect the fuel pump circuit and use specialized measuring tools to check whether the fuel pump's output and return flow rates are normal.