Throttle Movement Rate Effects on Transient Fuel Compensation in a Port-Fuel-Injected SI Engine

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.

• Record URL:
  • https://doi.org/10.4271/2000-01-1937
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/01487191
• Supplemental Notes:
  • Abstract reprinted with permission of SAE International.
• Authors:
  • Cowart, Jim S
  • Cheng, Wai K
• Conference:
  • CEC/SAE Spring Fuels & Lubricants Meeting & Exposition
  • Location: Paris , France
  • Date: 2000-6-19 to 2000-6-22
• Publication Date: 2000-6-19

Language

• English

Media Info

• Media Type: Web
• Features: References;
• Pagination: 11p
• Serial:
  • SAE Technical Paper
  • Publisher: Society of Automotive Engineers (SAE)
  • ISSN: 0148-7191
  • EISSN: 2688-3627
  • Serial URL: http://papers.sae.org/

Subject/Index Terms

• TRT Terms: Engine cylinders; Fuel injection; Spark ignition engines; Throttles
• Subject Areas: Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 01923494
• Record Type: Publication
• Source Agency: SAE International
• Report/Paper Numbers: 2000-01-1937
• Files: TRIS, SAE
• Created Date: Jun 30 2024 4:02PM