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00 Contour - CNG light only when regular gas is at half full

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  • 00 Contour - CNG light only when regular gas is at half full

    OK. I did my first CNG fill today and pumped in 3.745 gge

    The green ALT fuel light does not go on.

    I've had the car 7 days and only seen the solid green light when the regular gas tank was at half full and CNG was nearly empty. 1) When I first got the car it had 1/2 tank and nearly no cng, but the cng light worked until it ran out of cng. I topped off with regular gas and it no longer worked.

    As week went on, regular gas was used and when it dropped to less than 1/2 the cng light would sporadically work. At this point, the cng tank was nearly empty.

    I topped off the cng for the first time today and topped the regular gas as well and the cng light does not come on. Any correlation?

    My regular gas tank is at 3/4 full now. I wonder if the CNG will work when the regular gas drops to 1/2 full?

    I had a green OD/OFF error light that went on earlier and the check engine light went on. The engine stuttered and I thought it my be a transmission problem. Check engine has since turned off, but I'm going to Accurate Auto and have them scan it for me.

    I'm hoping it's something easy like a Throttle Position Sensor.Or a bad fuse.
    Last edited by BillHoo; 06-14-2012, 08:42 AM.

  • #2
    Re: 00 Contour - CNG light - troubleshooting

    I started the car up this morning:
    - Turned the key to the first position where the dash lights go on. Waited 20 seconds and the green alt fuel light came on.
    - Started the engine and the green light stayed on. Left it at idle for about 20 seconds.
    - Drove down the road at 20 mph - green light still on.
    - hit 30 mph and I felt the car shift over to regular gas and the cng shut off.

    Drove down the road, parked and went thru the same thing.

    After 3rd time, got fed up and kept it in regular gas mode. currently have a little more than half a tank of gas.
    Last edited by BillHoo; 06-14-2012, 08:41 AM.


    • #3
      Re: 00 Contour - CNG light only when regular gas is at half full

      OK. Looks like the ALT light no longer flashes (I'm guessing those were error codes?)

      I drove my Altima into work today - The Ford Contour had developed a flat (Yea, I know, this car is turning out to be a real winner!)

      Anyway, as I was doing some online research on the infamous CompuValve, I saw someone had posted their troubleshooting and how they used a "compuvalve reset trick" BUT THEY DIDN'T BOTHER TO DESCRIBE IT TO THE BENEFIT OF OTHERS WHO MIGHT BE TROUBLESHOOTING THE DARN THING!

      Later, I stumbled on a Ford Training Manual online for CNG and LPG Alt Fuel vehicles.

      HERE IS WHAT THEY PUBLISH AS A MEANS TO RESET THE COMPUVALVE (I'm going to give this a try tonight when I get home, If that does not worjk, I will check the fuses per the manual- there are 2 fuses and if they get switched, the green light will go on and run on CNG for 1 minute before the fuse burns out.) :
      1999 - 2002 Ford Bi-Fuel Vehicles March, 2002 4 - 21
      The compuvalve reset (1999 and later MY vehicles) allows long term fuel adaptive strategy to be reset using
      the ignition switch and the ALT fuel switch. Adaptive strategy should be reset after an engine condition has
      caused the vehicle to run rich or lean for an extended period of time or a heated oxygen sensor requires
      replacement. Doing so resets the compuvalve’s adaptive table to original factory values.
      Perform the following to complete a Compuvalve Reset:
      1. Key off.
      2. Perform the necessary vehicle preparation and visual inspection.
      3. Driver Selector (Alt fuel) switch in the ALT position.
      4. Turn key on, engine off.
      5. Cycle the ALT fuel switch from ALT to GAS 5 times in 10 seconds.
      6. Start the vehicle and operate it in the ALT fuel mode for 5 minutes.
      Last edited by BillHoo; 05-21-2012, 01:16 PM.


      • #4
        Re: 00 Contour - CNG light only when regular gas is at half full

        Well, I tried the above compuvalve reset trick and it did nothing. ALT light goes on for a few seconds, then winks out. Was raining cats and dogs, otherwise, I would have tried fixing the tire and checking the fuses. The tire is not only flat, but has fallen off the bead. I'll have to try and get it back on and reseal with some rubber cement. Maybe try that Youtube starter fluid trick where you spray it all inside with starter fluid, then light it! - the tire then self-inflates and seals.

        I got the service records from the seller and he told me the only trick he used to get it to start in cng was to turn the key to the first position, wait 20 seconds, then start it up.

        I looked at the records last night. Previous owner had the car since 2005. So I guess Washington Gas got rid of it as a fleet vehicle after 5 years of use? She's done regular oil changes and it seems to go through a lot of tires.

        In 2007 the car was towed into Koons Ford, College Park - only remarks was "owner said car died on the road and would not start" They replaced the PCM and clogged fuel line for around $779.

        In Sept 2011 the car was again towed into a shop unable to start.

        I'm only guessing the CNG system was never used in this car as it was driven mostly in DC and there are no places for them to refuel.

        Bringing it to Jerry's Ford in Alexandria, VA on Tuesday. They still have a CNG certified mechanic and hopefully all the diagnostic equipment.


        • #5
          Re: 00 Contour - CNG light only when regular gas is at half full

          I heard back from the dealer today.

          They say the wiring system looks burned out and cannot test the Compuvalve.

          They could replace the harness and if the compuvalve needs replacing, they would have to order from GTI in Canada. they estimate $4000

          Also found two nails in the driver-side rear tire and told me of a special 4 tires for $440 and a $100 rebate.

          I told them I was cutting my losses.

          So total for me is:
          $40 oil change
          $30 Air filter
          $105 for labor in diagnosing the CNG

          They would not entertain the idea of ordering remanufactured Compuvalves from that place in Tulsa, OK I had heard about.

          No one on this CNG Chat board seems to have had any experience with them, so I do not plan to drive 20 hours from virginia.

          I bought it at $2400.00. An additional $4000 might bring it to operation use as a CNG. If there were guarantees that it would work, I might consider it.

          Or I think I'll just sell the car as a regular gas car.
          Last edited by BillHoo; 05-30-2012, 03:41 PM.


          • #6
            Re: 00 Contour - CNG light only when regular gas is at half full

            Originally posted by BillHoo View Post
            I heard back from the dealer..................

            I told them I was cutting my losses.

            Or I think I'll just sell the car as a regular gas car...........
            That is the solution most have taken .


            • #7
              Re: 00 Contour - CNG light only when regular gas is at half full

              Sorry you've had so much trouble. I couldn't say what the problem is with your car, but I've had two Contours, one for 7 years and about 90000 miles and the other for 6 years and about 78000 miles and they've never had a serious problem, just typical maintenance issues that any car would have. I believe you might be able to find a rebuilt compuvalve for around $500, if that's the problem. I'm in Oklahoma and there are a few shops in the Tulsa area that might be able to help.


              • #8
                Re: 00 Contour - CNG light only when regular gas is at half full

                Sorry, after rereading your last post, I see that you've already rejected the idea of a rebuilt compuvalve.


                • #9
                  Re: 00 Contour - CNG light only when regular gas is at half full

                  to Dave - KSneedsCNG

                  Not sure if you got my detailed email regarding the car. The message system does not seem to have a way of checking the outbox, so I'm not sure if my messages were sent.



                  • #10
                    Re: 00 Contour - CNG light only when regular gas is at half full

                    Originally posted by dandlmelton View Post
                    Sorry, after rereading your last post, I see that you've already rejected the idea of a rebuilt compuvalve.
                    Not so much that I reject the idea of a rebuilt, but the Ford dealer doesn't want to work with rebuilt parts.

                    Add to that, no one on CNGChat has chimed in on their experiences with rebuilt compuvalves good or bad. It does not leave me with the warm and fuzzies that such parts really work.

                    As for me, Tulsa OK is far. If I don't sell the car by fall, I may head out there on a feral pig hunting trip and drop the car off to those guys in Tulsa if they give me a reasonable estimate.
                    Last edited by BillHoo; 05-31-2012, 03:58 PM.


                    • #11
                      Re: 00 Contour - CNG light only when regular gas is at half full

                      So I'm starting to pay more attention to some things when trying to start.

                      I drove home from work yesterday using gas. When I got home, I stopped the engine and waited a few minutes.

                      I turned the key to get the dash lights on. The Green ALT light went on and stayed steady. Waited 20 seconds, then started up the engine.

                      Green ALT light stayed on. I let it idle for 6 minutes before there was a hiccup and it switched over to gas.

                      I turned off the engine and repeated the procedure. This time, the Green ALT light only stayed on for 5 seconds. I heard a slight hum in the back (some kind of fuel pump motor?). Then a click and the battery light shut off and went back on just as the green ALT light shut off. The car starts in gas mode.

                      Did the same thing and the same result. After that, it won't start up on CNG until I wait a full day or two.

                      I'm guessing something got overloaded? Could it be a fuse or some kind of relay?

                      I think I saw someone post a wiring schematic somewhere for the bifuel contour. Maybe I cqan make some kind of a bypass?

                      This morning, I tried to start up on CNG again, but the green light won't stay on. I'm guessing it is flashing some kind of error code. 3 flashes BREAK 3flashes BREAK 3 flashes.
                      Last edited by BillHoo; 06-01-2012, 08:10 AM.


                      • #12
                        Re: 00 Contour - CNG light - Troubleshooting

                        I've noticed that the CNG light doesn't come on after a weekend of slow city driving.

                        After a week of long distance highway commuting the light comes on and flashes.

                        But the CNG which used to stay on for up to 7 minutes or so no longer works at all.

                        I wonder if there is because there is a short somewhere. The car has a history of electrical work being done and the dealer noted the harness was burned a bit. Maybe as the battery drains, and has lower amperage the compuvalve doesn't get enough juice to work?

                        I've not really look under the dash, but I fail to see a fusebox cover to check if maybe a fuse to the compuvalve is going out.

                        The guy who I bought the car from (selling for the previous owner) told me I had to turn the ignition and let it sit for 20-30 seconds before cranking when starting on CNG. This no longer works, leading me to believe that something has burned out.

                        It would be great if all I need is to replace a fuse or maybe find a wiring diagram and bypas the harnes and maybe wire the compuvalve directly to the battery.


                        • #13
                          Re: 00 Contour - CNG light - Troubleshooting

                          I got a chance to poke around and look for the CNG fuse box.

                          I found the fuses a 3 amp and a 10 amp fuse. Both look good and are not burned out. I made sure they were firmly inserted into their respective sockets.

                          I also found a wire coming out of the harness that was burned off!

                          I can only speculate that it came off the burned connector below it. I took a picture. Anyone know what this wire is supposed to do? Should I try reconnecting it? Maybe put an inline fuse there, so it doesn't keep burning off the connector?


                          • #14
                            Re: 00 Contour - CNG light - Troubleshooting

                            I think your idea is good - before you give up, try rewiring it with new wire and connectors and an inline fuse holder with fuse. The blue splice connectors in the picture don't look like factory splices - makes you wonder who's fiddled with the wiring and why?


                            • #15
                              Re: 00 Contour - CNG light - Troubleshooting

                              I had just that idea! Inline fuse would be a lot nicer than sizzling wire, or a car fire! - what do you think 3amp or 5 amp fuse?

                              Those blue connectors are vampire clips that someone put in there to jump the two tires together. I'll have to see where they lead.

                              I'll probably tinker this weekend.

                              On another note, I've noticed this car having really great fuel economy. The 2000 Contour is supposed to average 21 mpg (18 city/27 highway)

                              The first week I had the car, it averaged 21mpg. Then I took it to the dealer for inspection, diagnose the CNG, oil change and air filter.

                              The last tank, I tracked about 39mpg! Could there be CNG bleeding into the gasoline combustion that would help with mpg?

                              I've checked the odometer. I have a 17 mile commute to work and this morning it registered 16.3 - not too far off.

                              I filled the tank on Monday, and if this tank is like the last, I won't need to fill again until late next week.

                              I filled the CNG tank a few weeks ago. With the CNG not working, it should still be full. Maybe I'll try filling it in a few weeks and see if it will take any more.
                              Last edited by BillHoo; 06-21-2012, 09:02 AM.