No announcement yet.

2012 Civic CNG Tank Valve Issues?

  • Filter
  • Time
  • Show
Clear All
new posts

  • 2012 Civic CNG Tank Valve Issues?

    Hello Everyone

    New owner to a 2012 Civic CNG 102k miles. All maintenance up to date. After refilling the fuel gauge drops to empty and vehicle wont start. I've disconnected the battery and no luck. I scanned the car and no faults the 3 times it has happened this month after every fill up. If i let it sit overnight she fires up the next morning and the fuel gauge goes to full. Im pretty sure my tank main valve is sticking. I can hear the faint click (pilot vale) but the solenoid (loud ping) i can only hear the next morning. I may try lubing the valve. Could it be possible my fueling station is over filling my system? After filling the receptacle pressure gauge reads 4100 psi

  • #2
    where are you fueling home water? do you have a dryer could be freezing valve bad pressure sender telling the car that there is no fuel as what is your set pressure and what is your real shutdown pressure cheek with a certified gauge where you are fueling is it very hot as if you are fueling a 70 you should only have 3600 psi at shutdown 4100 is about right for 90 or a 100 check temp compensation chart try shutting down the compressor at 3000 and see if the car will start than take it to 3600 and try it again could be the fuel pressure sender going past rating and having no signal to the computer
    Last edited by cowboy; 05-05-2019, 09:45 AM.


    • #3
      I'm filling up at waste management facility 3600 psi. When I filled up last it was around 90 degrees when the gauge read 4100 psi so sounds about right according to the chart. Today I filled at 85 degrees and stopped the fill at approx 3800 psi and it didn't act up. I guess I can do a voltage drop across the tank solenoid and get a measurement when its operating as designed and compare reading when it is acting up. Whats also interesting is when the no start after fueling happens the fuel pressure regulator valve also doesn't "ping" even if I disconnect the battery and reconnect. Looking at the wiring diagram I see they have in common fuel shut off solenoid valve relay, i'm thinking I could also measure to see power and ground signals when it happens at the 4 pin relay in theory I could jump pin 1/2 on M10 and activate/ open the solenoids.


      • #4
        That solenoid times out in a second or two if the pressure doesn't raise. Helps prevent a leak. Also I don't think there is anything to oil.

        You have to depressurize the system to change the valve.......needs a special tool..

        Be very careful messing around with that kind of pressure


        • #5
          Part is expensive $1500 list It's not a do it yourself project.. dangerous pressures The dealer will charge list price and at least 4 hours labor.. A few have gotten Honda to replace out of warranty, Call Honda cust. service and open a case. Long shot but worth a try..


          • #6
            Unfortunately the civic is still doing it. Took it to the dealer to get diagnosed and they said no faults and operating ok. They suggested it is most likely a pressure sensor or tank valve. The CNG technician stated its hard to diagnose because they don't see very much CNG civics. They just replace tank valves and pressure sensors. Today with 70 miles of fuel remaining and taking 4.8 GGE Immediately after filling up, fuel gauge bars dropped and low fuel light came on and car died. I left it at the fill station going to go back later tonight or tomorrow to pick it up and it should start up normally. Any ideas?


            • #7
              Went back to station 4 hours later and cycled the ignition a few times and then heard the tank solenoid ping and sound of gas filling the lines heard. The fuel gauge started going up and then it restarted now and is back at home and running fine. Scanned it and no faults.


              • #8
                Thanks to Bill in Oregon I have a contact to talk to tomorrow in OKC that is knowledgeable with Civic GX. In the mean time I have created a case with Honda Of America to see what they suggest and point me to a good CNG dealer in the Arizona area.


                • gardenfairy
                  gardenfairy commented
                  Editing a comment
                  Grey CNG what is going on with your car? Is it fixed? Please share. Thankfully my 2008 that is acting up is a spare car at the moment but was hoping to give it to my daughter if she ever gets around to getting her license. We have two other CNGs that are 2009 and it would be devastating to lose my carpool access with my primary.

              • #9
                It still happens. I havent had the time to take it in. I've found a workaround that's been working. I noticed that if I put in less than 3 gallons at once it doesn't act up. So when I'm filling upand lets say it takes 5 gallons total , I'll pump 3 gallons disconnect start the vehicle and let it settle until the fuel gauge stops. Shut the car off and fill the rest of the 2 gallons. I've been doing this for the last 2 months and 10k miles and it hasn't acted up. Planning on taking it in one day but love my carpool access 😆


                • #10
                  Grey CNG, did you ever figure out a fix?
                  My 2012 Civic has started doing the same exact thing.
                  The first time with 4 miles to empty, then it worked fine for about 10 fillups, and then it happened again with 30 miles to empty.

                  I think my issue is the solenoid valve under the hood connected to the filter has gotten weak.
                  The second time it happened I shut off the main disconnect at the tank, tapped the casing of the solenoid, and heard a loud Click from the valve.
                  After that the fuel bars rose, I turned the fuel disconnect back on, and it cranked right up.
                  Can anyone corroborate this story? Does that sound right? I haven't started any research, I'm wondering if the solenoid portion could be replaced on the valve without opening any high pressure lines.
                  Also, does anyone have a good place to find a parts diagram for these cars?