×

CONTROL OF MANIFOLD VACUUM IN SKIP FIRE OPERATION

  • US 20140041641A1
  • Filed: 08/07/2013
  • Published: 02/13/2014
  • Est. Priority Date: 08/10/2012
  • Status: Active Grant
First Claim
Patent Images

1. A method of selectively reducing intake manifold pressure in a skip fire engine control system to help purge a fuel vapor canister, reduce pressure within a brake vacuum booster reservoir or vent gas from a crankcase interior, the method comprising:

  • operating an engine in a skip fire manner to generate a desired torque level using a throttle set at a substantially open position;

    further closing the throttle to reduce the intake manifold pressure in order to perform a manifold vacuum-related process selected from the group consisting of

         1) purging the fuel vapor canister;

         2) reducing pressure within a brake vacuum booster reservoir; and

         3) venting gas from the crankcase interior;

    increasing an engine firing fraction to help maintain the desired torque level; and

    after the manifold vacuum-related process has been performed, returning the throttle to the substantially open position and decreasing the firing fraction.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×