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Compressor Oil Carryover webinar FREE

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  • Compressor Oil Carryover webinar FREE

    on Jan. 24th. register here : http://campaign.r20.constantcontact....4-e0adee5721fe

    "There's an elephant in the room with CNG: oil carryover from CNG stations is a leading cause of costly natural gas vehicle component and engine failures. It is misunderstood in root cause, underestimated in cost and frequently undiagnosed."

    "Fleets experiencing undiagnosed oil carryover spend literally thousands of dollars replacing damaged or failed components, only to have to replace them again because the root problem is not solved."
    Last edited by Lakewood90712; 01-10-2019, 05:30 PM.

  • #2
    First component to fail.......Fuel Injectors


    • #3
      I was very bullish on this when operating the Long Beach stations on controlling oil carry over. I have been shocked at how many station operators are lackadaisical on this subject.


      • #4
        Seems like it does not take much oil to take out a $170 fuel injector on the GX - usually the #1. Especially on the GXs that only have the single fuel filter (2 - 2000 GXs 104K/100k replaced many fuel injectors, 2008 GX 45k none yet). When I replaced the fuel filters there was not much in there. Never been able to get a GX fuel injector serviced where it works properly so I do not try anymore.. .


        • #5
          How do you know if it's oil taking out the injectors? I've got a 2009 GX with 160k on it and I'm about to replaced my 3rd injector (all in different positions). My first injector started acting up at about 120k. Debating if I should just replace the last two and get it over with. Any idea on how long these injectors are supposed to "normally" last?


          • #6
            Motoboy, the 2009 GX has two filters and the 2000 GX has one which suggests to me that the 2009 would be better at getting the oil out of the fuel. I'm aware of a station compressor filter issue that occurred in very close proximity to both my 2000 GXs (within a week) needing the #1 fuel injector replaced. I've had to replace other fuel injectors but not at the rate I've replaced the number 1 on the 2000 GXs. The logic I used to come up with why the number 1 being more susceptible is like an inertial separator on a turbine engine or a dust/dirt leg prior to a gas appliance the denser material takes the straighter path. When you get to the end there is no place to go. When I replace the injectors I clean the fuel rail out. I removed oil from the rail end close to the #1 injector during these events. If you are getting 120K+ miles from an injector, that seems pretty good since these injectors run dry gas and are not getting continuously cleaned by detergent in gasoline and gasoline. On my 2008 GX (two filters) I have 45K and no replacements yet. I never replaced more than 2 at once. I'd buy the injectors but only replace on an as needed basis because of the cost ($170 each). It only takes a 10 mm socket wrench and about 10-15 minutes to replace them on the 2000 GX. I'd replace the fuel filters if you have not already done this before I'd replace a working injector because that is preventative maintenance. Just my take. If you are paying someone to do this for you then I guess there are other considerations that I do not have.


            • motoboy
              motoboy commented
              Editing a comment
              Good info. I replaced both filters about a year ago and had very little oil in the bottom of the high pressure filter. From what I hear the Kwik Trip stations I fill up at around here are pretty good at maintaining their systems/filters as they run most of their tanker trucks on CNG. Seems like I'm bumping up against the normal life of injectors, haven't had one fail in the same position yet. The one thing that does puzzle me is when I get a failure it will be intermittent and I'll get a rich misfire (negative fuel trim) plus (when it's acting up) I can see if I just turn the key on and watch the fuel rail pressure it will drop like a rock after a few seconds when the fuel supply solenoid valve turns off. I sent an injector in to RC Fuel Injection out in California and when they finally got back to me they said the injector was junk as they couldn't get it to flow enough volume on the test bench, this seems counter intuitive from what I'm seeing. Maybe there's something about the failure mode I don't understand, like the pintle wears out, creates friction and hangs open sometimes but also doesn't open enough at times. I don't rev over 4000 rpm most of the time so I guess I might not see the low flow end of the failure. I replace my own injectors, probably takes me 45-60 minutes taking my time, that gap between top of the engine and bottom of cowl is just wide enough to pinch my forearms when taking the fuel rail off, but yeah not the worst job in the world.

          • #7
            At a NGV round table I remember hearing from a Ford or Honda engineer that talked about the challenges of designing a CNG fuel injector. It did not have the gasoline to clean and cushion the injector over its life.


            • #8
              I worked for a company that does commercial upfits for small buses. We saw hundreds of failures due to carryover oil, however none of those had injector failures due to it. We primarily did ford v10’s with Bosch injectors (dedicated system). Nearly every time there was a failure, it was the regulator. One after another after another. Rotorex was the worst, but any design struggles to be reliable with that much carryover oil.


              • #9
                Fun fact about ford engineers... In 2013 I worked with 2 ford pcm calibration engineers who were pulled from working on focuses to do CNG cal’s for Westport. We had 30 vehicles that kept throwing rich codes and after working with them, figured out that they had been programming the CNG cals based on 14.7:1 as stoich.. we all learned different things that day.


                • #10
                  Well - just replaced two fuel injectors this weekend on my son's 2000 GX. There was a little bit (couple tiny beads) of oil in the #1 injector and I could not tell on #2. Both were causing trouble, #1 & #2 misfire codes as well as random misfire code. Tried just one of them but was still running rough (better but not ideal) so we replaced #2 as well and the roughness fully disappeared. Replaced the fuel filter on this car about a year ago. I was checking out some folks on YouTube that were rebuilding injectors (new spacers/o-rings/seals/filters, cleaning in sonic bath) but did not head down that path based on my prior experience getting the injectors professionally rebuilt and still having issues with those injectors. My pile of old injectors is getting larger.