Abstract: Methods and systems are provided for an adaptor for a capless filler pipe of a fuel tank for leak detection testing of a vehicle. In one example, the system may include a threaded hollow shaft having a top end able to receive a nozzle of a leak detection machine, the hollow shaft inserted through a mouth of a filler pipe of a fuel tank, a gasket arranged on the hollow shaft, and an end cylinder having an elastic piece on the hollow shaft configured to create an airtight seal with the fuel mouth. In this way, the adaptor may restrict gas flow through a defined flow path through the adaptor, and not through any other flow paths during leak detection testing.

Abstract: Methods and systems are provided for an adaptor for a capless filler pipe of a fuel tank for leak detection testing of a vehicle. In one example, the system may include a threaded hollow shaft having a top end able to receive a nozzle of a leak detection machine, the hollow shaft inserted through a mouth of a filler pipe of a fuel tank, a gasket arranged on the hollow shaft, and an end cylinder having an elastic piece on the hollow shaft configured to create an airtight seal with the fuel mouth. In this way, the adaptor may restrict gas flow through a defined flow path through the adaptor, and not through any other flow paths during leak detection testing.

Abstract: Methods and systems are provided for operating an engine to generate vacuum for a subsequent leak detection routine. During a selected key-off condition, a starter motor is operated to spin the engine unfueled and generate intake vacuum for the leak detection. Fuel vapors drawn during the spinning are stored in an auxiliary canister that is purged along with a main canister during purging conditions.

Abstract: A vehicle is provided with a fuel system, a controller, and a diagnostic module with an orifice, a pressure sensor, and a pump, the module connecting the fuel system to atmosphere. The controller measures a reference pressure across the orifice to provide a threshold, isolates the fuel system, and provides a code in response to comparing a series or measured pressures to the threshold. A method for performing an evaporative leak diagnostic is provided. A valve in a diagnostic module is commanded to a vent position. A pump is operated to measure a reference pressure across an orifice to provide a threshold. A valve is commanded to a test position. The pump is operated to place the fuel system in a low pressure state, and a series of pressures in the fuel system is measured. A diagnostic code is provided after comparing the series of pressures to the threshold.

Abstract: Methods and systems are provided for operating an engine to generate vacuum for a subsequent leak detection routine. During a selected key-off condition, a starter motor is operated to spin the engine unfueled and generate intake vacuum for the leak detection. Fuel vapors drawn during the spinning are stored in an auxiliary canister that is purged along with a main canister during purging conditions.

Abstract: A vehicle is provided with a fuel system, a controller, and a diagnostic module with an orifice, a pressure sensor, and a pump, the module connecting the fuel system to atmosphere. The controller measures a reference pressure across the orifice to provide a threshold, isolates the fuel system, and provides a code in response to comparing a series or measured pressures to the threshold. A method for performing an evaporative leak diagnostic is provided. A valve in a diagnostic module is commanded to a vent position. A pump is operated to measure a reference pressure across an orifice to provide a threshold. A valve is commanded to a test position. The pump is operated to place the fuel system in a low pressure state, and a series of pressures in the fuel system is measured. A diagnostic code is provided after comparing the series of pressures to the threshold.