Why is there no sound from the fuel pump of an EFI motorcycle?
3 Answers
EFI motorcycle fuel pump may have no sound due to loose ECU wiring connections, resulting in poor signal transmission. An EFI motorcycle is a new type of motorcycle that uses a microcomputer to control the fuel injector to supply fuel to the working cylinders based on engine load, while non-working cylinders receive no fuel. Compared to traditional carburetor motorcycles, EFI motorcycles are more fuel-efficient, saving over 20% more fuel than their carburetor counterparts. Below is an introduction to the structural components of an EFI motorcycle: ECU: The abbreviation for Electronic Control Unit, which is essentially an integrated circuit board responsible for converting electrical signals from various sensors into digital signals. It processes these signals using programs stored in the circuit board's rewritable memory and then sends control signals to manage fuel injector operation and high-voltage coil ignition. Fuel Injector: A precision component responsible for spraying and atomizing fuel, typically installed at the intake pipe end of the throttle body.
I've been riding EFI motorcycles for over ten years and often encounter situations where the fuel pump doesn't make any sound. The first thing to do is check the fuse, which is usually hidden under the seat or near the battery. A blown fuse is a common issue—just pull it out gently and replace it with a new one to test. If the fuse is fine, then check whether the fuel pump relay is loose or burnt out. Last time, I found dirty relay contacts, and cleaning them solved the problem. If there's an issue with the wiring, such as aged or short-circuited wires, the fuel pump naturally won't work. Also, low battery voltage can affect the fuel pump's startup—use a multimeter to check the power level. Remember, don't try to disassemble it blindly. If the problem persists after a few attempts, it's best to consult a professional mechanic to avoid getting stranded on the road. Regular checks on these components can save a lot of trouble.
If the fuel pump makes no sound, it's most likely due to a blown fuse or a malfunction in the pump itself. First, ensure the battery has sufficient charge when igniting, otherwise the fuel pump won't have power. Turn the key and listen carefully—normally, there should be a humming sound. If it's silent, check the fuse box location, usually near the frame, and replace the fuse to see if it restores function. A faulty relay is another possibility; if you don't hear the clicking sound of engagement, it needs replacement. Short circuits or corroded connections are also common, especially at wire terminals on older motorcycles, which are prone to oxidation. I once encountered a seized fuel pump motor during repairs, causing the sound to disappear. Address symptoms promptly to avoid fuel supply failure and potential accidents while riding. Always ensure power is disconnected for safe operation before working on it.
