What Causes the Fuel Nozzle to Keep Tripping During Refueling?
3 Answers
The reasons why the fuel nozzle keeps tripping during refueling are: 1. Blockage or poor fuel flow in the fuel line; 2. The vent pipe next to the fuel filler is blocked or deformed; 3. High pressure inside the fuel tank due to hot weather, causing fuel to splash easily during refueling; 4. Relatively fast refueling speed, leading to fuel splashing and nozzle tripping; 5. Excessively twisted structure of the fuel tank pipe. Refueling tips include: 1. Refuel when the tank is one-quarter full; do not wait until it is empty; 2. Do not overfill the tank; leave some space; 3. Do not mix different types of fuel; do not add diesel or kerosene to gasoline; 4. Follow the fuel grade requirements indicated on the fuel cap; 5. Refuel at medium to large gas stations; using sulfur-containing low-quality gasoline can poison the oxygen sensor.
I run an auto repair shop and encounter too many car owners complaining about the fuel pump nozzle shutting off prematurely. Nine times out of ten, it's related to the charcoal canister. The fuel vapors in the tank need to be absorbed by the charcoal canister. If it's clogged, the vapors can't escape, and the pump nozzle detects abnormal pressure and immediately cuts off the fuel supply. Last time, I met a Tiguan owner whose pump nozzle shut off five or six times every refuel. Upon disassembly, we found the charcoal canister was full of sand. Another common issue is the fuel tank vent pipe being crushed, often caused by undercarriage impacts during repairs. This happens especially often in summer when high temperatures increase fuel vapors. The fix is actually quite simple—replacing the charcoal canister costs just a few hundred bucks.
When I first took over my dad's old Accord, I noticed this issue: the fuel nozzle would click and stop during refueling, making the attendant think the tank was full. Later, I learned it was due to a design flaw in the fuel tank. The fuel pipe was designed in an S-shape, causing turbulence when fuel rushed in, which triggered the nozzle's overflow protection. Now, every time I refuel, I ask the attendant to pull the nozzle out a few centimeters and slow down the flow rate, which helps a lot. A reminder to everyone: don’t play with your phone while refueling—keep an eye on the nozzle angle. Inserting it at an angle can cause gasoline to splash into the sensor hole, making the machine think the tank is full and stop automatically.
