No announcement yet.

EGR Operation.

  • Filter
  • Time
  • Show
Clear All
new posts

  • EGR Operation.

    Has anyone any idea how the egr operates on on the Fortuner. Mine seems to stay open at about 30 to 55 percent most of the time including at idle, engine hot or cold. The only time the EGR valve closes is on acceleration in second gear and higher. This is not the way I thought they worked. Can anyone please enlighten me? Maybe it's a new technology thing and I need to be brought up to speed. Fuel useage is heavy, 10l/100 or more sometimes, but engine starts and runs well unless dpf need a regen. Thanks in advance.

  • #2
    Hey David, what’s happening is correct👍
    i guess the first thing is to know that an EGR on a diesel has some different operating conditions than a petrol car.

    A diesel is classed as an excess air engine, so unlike a petrol the cylinder will always receive a full charge of air. The RPM is controlled by how much fuel is injected.

    So at idle the EGR will open to allow inert gas to enter the combustion chamber this will replace excess oxygen not needed for combustion. Less oxygen results in less Nox emissions and it not running so lean say like 60:1 air/ fuel ratio.
    when cold EGR bypasses the cooler.
    under cruise it will be open.
    under load it will close. hence the EGR doesn’t rob engine of power which is a common myth

    hope this helps

    cheers, Spook


    • #3
      Thanks mate, still catching up with new technology. The earlier systems I was used to closed the egr valve at cold start up and opened as engine warmed up. Also if engine had been idling for a while (I think 2 minutes) the valve closed until vehicle moved off again. Geez it's hard trying to keep up with this stuff. Thanks again.


      • Spook1205
        Spook1205 commented
        Editing a comment
        It is hard to keep up to date with technology but something I am always learning about.

        Was that a petrol you looked at before cause they will always be closed at idle or load conditions. Work on cruise or low load.

    • #4
      No mate it was a Jeep wrangler 2.8 diesel engine, made by VM Motori. An incredible motor. Could withstand any kind of punishment and yet much more simple than this Toyota engine. I think some of the electronics were more advanced than this motor as well and that from a ten year old engine. the cooling system on this one is a doozy from what I have been told..Still we'll wait and see. So far this has been a strong reliable engine. Fuel economy is the only complaint. 10l/100 plus, is a bit much in this day and age. Hopefully it will get sorted. Could be a dpf issue. Blocked exhausts don't help fuel economy.
      Last edited by davidd; 13-12-2017, 09:44 PM.


      • Spook1205
        Spook1205 commented
        Editing a comment
        Ah jeeps, welded a few cracked exhaust manifolds in them lol ( 6 cyl petrol)
        10 ltrs per 100 is pretty high mate.
        Can you grab a half decent multi meter and paper clip / or something and back probe middle wire in DPF sensor. See what voltage is at idle then give it a decent full throttle rev and see max voltage?
        If you think you have DPF issues would love to see what voltages are.