초록 ▼

Automotive internal combustion engine control and diagnostics responsive to an up-to-date on-board estimate of fuel reid vapor pressure (RVP). An on-board fuel vapor recovery system traps fuel vapors released from a fueling system and is controlled to release the vapors to the engine for consumption

Automotive internal combustion engine control and diagnostics responsive to an up-to-date on-board estimate of fuel reid vapor pressure (RVP). An on-board fuel vapor recovery system traps fuel vapors released from a fueling system and is controlled to release the vapors to the engine for consumption therein, along with an injected fuel charge under closed-loop engine air/fuel ratio control. The change in the injected fuel charge required to maintain, under closed-loop control conditions, a target air/fuel ratio in the presence and in the absence of the released fuel vapors is applied along with fuel temperature information to estimate RVP, and the RVP estimate is applied under coldstart operating conditions to adjust engine fueling to account for corresponding changes in the vaporization characteristic of the fuel and is applied, when determined to be relatively high, to indicate potential false positives in fuel vapor recovery system diagnostics.

대표청구항 ▼

[ What is claimed is:] [1.] A method for estimating automotive internal combustion engine fuel volatility in an internal combustion engine selectively receiving fuel vapors trapped in a fuel vapor recovery system, comprising the steps of:admitting fuel vapors from the fuel vapor recovery system to t

[ What is claimed is:] [1.] A method for estimating automotive internal combustion engine fuel volatility in an internal combustion engine selectively receiving fuel vapors trapped in a fuel vapor recovery system, comprising the steps of:admitting fuel vapors from the fuel vapor recovery system to the engine for combustion therein;determining a change in engine fueling resulting from the admission of fuel vapors from the fuel vapor control system to the engine; andestimating fuel volatility as a function of the determined change.