Evaporative emissions leak tester and leak test method
First Claim
1. A method for testing for a leak in an evaporative-emissions system of a motor vehicle using an evaporative-emissions-leak tester, the method comprising steps of:
- recording a fuel-vapor pressure-rise rate with an engine of the vehicle turned “
off”
;
recording a value that directly correlates with an out-gassing effect created by a volume, blend, and temperature of fuel;
applying a vacuum to a fuel-delivery system of the vehicle;
recording vacuum decay; and
determining a leak rate by offsetting the recorded fuel-vapor pressure-rise rate with the recorded decay.
1 Assignment
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Accused Products
Abstract
A tester and method for testing for a leak in an evaporative-emissions system of a motor vehicle comprise a/an power supply, computer, display communicating with the computer, analog-to-digital board communicating with the power supply and computer, pressure sensor communicating with the board, housing into which the power supply, board, and sensor are integrated, stationary enclosure, and test connection including a hose to the enclosure. A fuel-vapor pressure-rise rate is recorded with an engine of a motor vehicle turned “off.” A value is recorded that directly correlates with an out-gassing effect created by a volume, blend, and temperature of fuel. A “purge” cycle occurs at idling of the vehicle within a short period of time. The engine applies a vacuum to a fuel-delivery system of the vehicle. Vacuum decay is recorded. A leak rate is determined by off-setting the recorded fuel-vapor pressure-rise rate with the recorded vacuum decay.
46 Citations
10 Claims
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1. A method for testing for a leak in an evaporative-emissions system of a motor vehicle using an evaporative-emissions-leak tester, the method comprising steps of:
-
recording a fuel-vapor pressure-rise rate with an engine of the vehicle turned “
off”
;recording a value that directly correlates with an out-gassing effect created by a volume, blend, and temperature of fuel; applying a vacuum to a fuel-delivery system of the vehicle; recording vacuum decay; and determining a leak rate by offsetting the recorded fuel-vapor pressure-rise rate with the recorded decay. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification