System and method for detecting leaks in a vapor handling system
AssigneeGeneral Motors Corporation
InventorSam R. Reddy
Life of this patent
Estimating the term…
Abstract
This invention relates to a diagnostic system that detects a leak in an engine vapor handling system by checking whether a predetermined pressure or vacuum is attained in a fuel tank when a corresponding temperature change occurs in the fuel tank while the engine was not running.
Claims9
A diagnostic system for detecting a leak in a vapor handling system for an engine and having a fuel tank, said diagnostic system comprising:
- a means for detecting a temperature change in the fuel tank while the engine is not running,
- a means for detecting a pressure change in the fuel tank while the engine is not running,
- and a means for determining whether or not a leak exists in the vapor handling system by comparing said temperature change with said pressure change.
A diagnostic system for detecting a leak in a vapor handling control system for an engine and having a fuel tank, said diagnostic system comprising:
- a means for detecting a predetermined increase of temperature in the fuel tank while the engine is not running,
- a means for detecting a predetermined pressure level of the fuel tank while the engine is not running,
- and a means to indicate a leak in the vapor handling system if the predetermined pressure level is not attained while the predetermined temperature increase is attained.
A diagnostic system for detecting a leak in a vapor handling system for an engine and having a fuel tank, said diagnostic system comprising:
- a means for detecting a decrease of temperature in the fuel tank, while the engine is not running,
- a means for detecting a predetermined vacuum level in the vapor handling system while the engine is not running,
- and a means for indicating a leak in the vapor handling system if the predetermined vacuum level is not attained while a predetermined temperature decrease is attained.
A method of detecting a leak in a vapor handling system for an engine and having a fuel tank, comprising the steps of:
- measuring a temperature change in said fuel tank while the engine is not running,
- measuring a pressure change in said fuel tank while the engine is not running,
- and determining whether or not a leak exists in the engine vapor handling system by comparing said temperature change with said pressure change.
A method of detecting a leak in a vapor handling system for an engine and having a fuel tank, comprising the steps of:
- measuring a temperature increase in said fuel tank while the engine is not running,
- measuring a pressure in said fuel tank while the engine is not running,
- and indicating a leak if said pressure is less than a selected pressure while said temperature increase exceeds a selected increment.
A method of detecting a leak in a vapor handling system for an engine and having a fuel tank, comprising the steps of:
- detecting a temperature decrease in said fuel tank while the engine is not running,
- measuring a vacuum level in said fuel tank while the engine is not running,
- and indicating a leak if a predetermined vacuum level is not attained while said temperature decrease exceeds a selected decrement.
A diagnostic system for detecting a leak in a vapor handling system for an engine and having a fuel tank, said diagnostic system comprising:
- means for determining whether the pressure in said fuel tank changes in a predetermined manner in response to changes in temperature while the engine is not running.
Dependencies are inferred from the claim text.