2012 cruze 1.4 constant evap purging

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  • STURNER
    Member
    • Oct 2014
    • 91

    2012 cruze 1.4 constant evap purging

    Car came in needing a new valve cover due to stuck pcv. After repair and resetting fuel trims I noticed the trims started increasing again. The purge solenoid was working at about 12% which I thought was odd. P0171 set again. Turn off and start again, after about 60 seconds it starts to purge, adds fuel, sets code, and vent stays open. I find a lot of info on the web for bad purge valves on these and p0496 with folks replacing the valves and claiming to fix the problem. I can unplug the valve and install a noid light and see that it is being commanded on so I cant blame it on the valve. I plugged the port on the intake and trims go 0-2%. I looked for a new calibration for this and found nothing. Anybody ran into this before or have any thoughts on direction?
  • Witsend
    Banned
    • Nov 2012
    • 2942

    #2
    Maybe the Canister Vent valve back at the canister is just hung wide open and your just still pulling air through the lines after the fumes have already been long vented?

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    • BRIAN617
      Senior Member
      • Dec 2016
      • 153

      #3
      Originally posted by STURNER
      Car came in needing a new valve cover due to stuck pcv. After repair and resetting fuel trims I noticed the trims started increasing again. The purge solenoid was working at about 12% which I thought was odd. P0171 set again. Turn off and start again, after about 60 seconds it starts to purge, adds fuel, sets code, and vent stays open. I find a lot of info on the web for bad purge valves on these and p0496 with folks replacing the valves and claiming to fix the problem. I can unplug the valve and install a noid light and see that it is being commanded on so I cant blame it on the valve. I plugged the port on the intake and trims go 0-2%. I looked for a new calibration for this and found nothing. Anybody ran into this before or have any thoughts on direction?
      12% Purge at idle is normal, problem is the sticky valves. I've noticed when commanded through their DC% range they stick wide open even though the duty cycle changes.

      There is also trouble with the PCV hose (from intake to turbo inlet) and the anti return valve in the intake for the PCV system. There is a TSB for it. I'll try to find it.

      Comment

      • BRIAN617
        Senior Member
        • Dec 2016
        • 153

        #4
        There have been problems with P1101 set in the Cruze or Sonic with the 1.4 turbo engine. Lean codes may also be set with possible rough running or idle surge complaints. The problem is caused by unmetered air entering the engine through the PCV system. Several

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        • Witsend
          Banned
          • Nov 2012
          • 2942

          #5
          Sounds like another thousand dollar problem on a five hundred dollar car. First a new valve cover and then if you don't see a little orange tit through a peep hole it will need a new intake.

          Comment

          • STURNER
            Member
            • Oct 2014
            • 91

            #6
            Thanks a lot. That's a great piece of information.

            Comment

            • crackerclicker
              Senior Member
              • May 2008
              • 400

              #7
              Originally posted by Witsend
              Maybe the Canister Vent valve back at the canister is just hung wide open and your just still pulling air through the lines after the fumes have already been long vented?
              Hi Wits,

              Just for future reference, the vent valve is typically always open anyway. Closes for leak testing, not purging.

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