Throttle Movement Rate Effects on Transient Fuel Compensation in a Port-Fuel-Injected SI Engine Massachusetts Institute of Technology

Format:

Book

Conference/Event

Author/Creator:

Cowart, Jim S., author.

Conference Name:

CEC/SAE Spring Fuels & Lubricants Meeting & Exposition (2000-06-19 : Paris, France)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2000

Summary:

Throttle ramp rate effects on the in-cylinder fuel/air (F/A) excursion was studied in a production engine. The fuel delivered to the cylinder per cycle was measured in-cylinder by a Fast Response Flame Ionization detector. Intake pressure was ramped from 0.4 to 0.9 bar. Under slow ramp rates (1 s ramp time), the Engine Electronic Control (EEC) unit provided the correct compensation for delivering a stoichiometric mixture to the cylinder throughout the transient. At fast ramp rates (a fraction of a second ramps), a lean spike followed by a rich one were observed. Based on the actual fuel injected in each cycle during the transient, a x-τ model using a single set of x and τ values reproduced the cycle-to-cycle in-cylinder F/A response for all the throttle ramp rates. The F/A excursions in the fast transients were attributed to the failure of the dynamic fuel pulse to deliver the extra fuel compensation to the intended cycle and the EEC error in estimating the air flow which resulted in the incorrect fuel compensation

Notes:

Vendor supplied data

Publisher Number:

2000-01-1937

Access Restriction:

Restricted for use by site license