Fuel Rail Pressure Rise during Cold Start of a Gasoline Direct Injection Engine

2012-01-0393

04/16/2012

Event
SAE 2012 World Congress & Exhibition
Authors Abstract
Content
Gasoline direct injection provides reduced engine emissions, increased power, and increased fuel economy as compared to port fuel injection (PFI). Reduced emissions are largely due to starting the engine using high fuel pressure (up to 150 bar) and injecting into the compression stroke. During a cold start, fuel pressure must be increased from lift pump pressure (typically 4 to 6 bar) to desired injection pressure (typically 25 bar minimum). Start times are therefore impacted by the high pressure pump's ability to quickly build fuel pressure during crank.
This study investigates the temperature and pressure affects during engine soak which allow vapor and air to form in the fuel system. Vapor and/or air in the system cause a slower fuel pressure build and increases start times. The scope of the problem and possible solutions were determined using theoretical and empirical testing. By preventing air and vapor formation in the fuel system, reduced and more consistent start times are achieved.
Meta TagsDetails
DOI
https://doi.org/10.4271/2012-01-0393
Pages
9
Citation
Burke, D., Foti, D., Haller, J., and Fedor, W., "Fuel Rail Pressure Rise during Cold Start of a Gasoline Direct Injection Engine," SAE Technical Paper 2012-01-0393, 2012, https://doi.org/10.4271/2012-01-0393.
Additional Details
Publisher
Published
Apr 16, 2012
Product Code
2012-01-0393
Content Type
Technical Paper
Language
English