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Service Bulletin concerning Crown Vic rough idle

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  • #16
    Re: Service Bulletin concerning Crown Vic rough idle

    Originally posted by Lancer Automotive Group View Post
    Ask them if the $270 is just for a fuel system flush or do they actually remove the injectors and clean them.
    What would be a normal price range for both services (system flush vs. remove injectors and clean)? We've been out our truck for almost a month now and just need to get it done ASAP.


    • #17
      Re: Service Bulletin concerning Crown Vic rough idle

      Kameron 13462 et al,

      Did you ever do your service on your 03 Crown Vic? I have a 2003 Crown Vic CNG P70 (Extended Chassis) with 45k miles and don't think the filter has ever been changed. Since I am having misfires on #8 I figured that I would start with the filter first since it needs to be done anyway and hope injector cleaner will help before I dig into plugs, coils and injectors. I called SeaFoam today and they said that Sea Foam is safe for a CNG vehicle so I thought I'd put it in the filter bowl and run it through.

      I read this and other threads, ordered my Motorcraft Filter #FG-1088 (Amazon for $27.88) and went to install it today.

      Here is what I encountered:

      I jacked up the car and looked for the "skid plate cover" that cng-vic-ut mentions in this thread:

      However, my skid plate has the parking brake cable attached to it.

      Do I need to remove the cable so I can get access to the filter housing? I also don't see a red shut off valve.

      Is there a chance that Ford only used electronic solenoids on the 2003 models? I even removed the tank cover in the trunk looking for a shut-off and can't find one. I also looked up from underneath following the fuel line back to the tanks.

      I got impatient and slightly cracked open the screw at the bottom of the filter housing ( I know - I risked a lot of CNG escaping), and it stopped once the pressure was released.

      Any ideas? Do I risk changing the filter without a manual shut-off? Is there one?

      Thanks all.
      Last edited by Deeta; 01-07-2009, 10:48 PM.


      • #18
        Re: Service Bulletin concerning Crown Vic rough idle

        Hi Deeta,

        Unfortunately as I found out, Ford elected to "decontent" the manual shut-off valve on the 2003 model. The only way to safely cut-off the high-pressure tanks is to manually turn off the tank valves ON EACH TANK. This makes changing the fuel filter a royal pain. Mine came out sparkly clean after 30K miles, so I don't plan on doing this service again anytime soon, and yes, I did the injector cleaning service as well.

        I DO NOT RECOMMEND unplugging fuse #5 in the engine bay to disable the solenoid tank valves and regulator, and crack the bleed screw (as you did). If you have a leaky tank valve, or a valve stuck in the open position, cracking that bleed screw can put you in a VERY, VERY precarious situation.

        FYI to anyone doing this service, treat those O-rings with tender loving care. They fracture really easy.
        2003 Ford Crown Victoria CNG


        • #19
          Re: Service Bulletin concerning Crown Vic rough idle


          " read this and other threads, ordered my Motorcraft Filter #FG-1088 (Amazon for $27.88) and went to install it today. "

          When I search for this on Google, I get fuel filters - and a picture of a "normal" little gasoline fuel filter. Could you check the part number for me?

          There seems to be one on Amazon now, but it is $42.91 from Troy Ford - with no picture - is that who you ordered from?




          • #20
            Re: Service Bulletin concerning Crown Vic rough idle

            You can purchase the coalescent filter for the Crown Victoria by clicking on this link Also, you do not need the shut off valve to depressurize the fuel system. When the car is off and the key is out of the ignition, the electronic valves on the end of the tanks remain in the closed position. The only exception to this is if the car has additional non-factory tanks that do not have electronic shut off valves. In this case you would need to manually close down the valves on these additional tanks. Once the car is off and any manual valves are closed, access the filter housing under the vehicle by removing the skid plate. With the skid plate removed the coalescent filter housing is exposed. On the bottom of the lower filter bowl there is a drain plug. Use the appropriate size hex key wrench to slowly loosen the drain plug until you here gas escaping (no more two to three full turns). Oil may begin oozing out, just have a paper or cup ready to catch the oil. If you get a lot of oil, you will definitely want to replace the old coalescent filter with a new one. Wait until the gas stops hissing out (3 min at the most) and the CNG fuel lines will be depressurized. Finish removing the drain plug and then use a crescent wrench, by attaching it to the flats on the bottom of the filter bowl, to remove the filter bowl and expose the coalescent filter. Pull down on the filter to remove it from the male tube attached to the upper housing. Clean out the filter bowl and threads. Replace the o-ring seated into the grove at the top of the lower filter bowl. Thread the new drain plug and o-ring into the bottom of the lower filter bowl. Make sure when you are venting the gas to perform this procedure in a well ventilated area. Also, make sure you have a filter with a new drain plug and o-ring, because the pressure will likely break the o-ring as you are venting the CNG. Install the new filter onto the male post of the upper filter housing and rethread the lower filter bowl onto the upper filter housing. Do not try to over tighten the drain plug or lower bowl when reassembling everything. Due to the flex in the filter assembly, you will only be able to get it so tight so don’t force it. When you perform any drain and fill procedures with either the Ford PM5 injector cleaner or isopropyl alcohol, leave the old filter in place so no dirt, grime or anything can get into the pressure regulator or the injectors. Better safe than sorry, besides the cleaner passes through the filter just fine. The reason they say to only fill the bowl ¾ full is so the solvent does not spill everywhere when the filter displaces the liquid. Because the PM5 is so aggressive, follow it up with an isopropyl alcohol flush to get the PM5 residue out of the system. Usually two PM5 flushes performed according to the ford bulletin procedure, followed by an isopropyl alcohol flush will take care of the rough idle, dying and lean code problems for the dedicated vehicles. The PM5 acts as a solvent to break down and clean out the carry over compressor oil that has solidified inside the injectors and fuel lines. The heat of the engine turns the oil into a semi solid vanish like deposit. When replacing the filter I recommend using only the Parker CLS112-6 grade 6 filter because it catches 99.97% of this carry over oil. The grade 10 filter, while slightly cheaper, does not do as good of job catching the carry over compressor oil suspended in the CNG as an aerosol. The CNG filtration systems in the Fords were under engineered. The diagrams from Parker for natural gas vehicles shows using two coalescent filters; one before the regulator and one after. This is how the Honda Civic GX's are set up since they were redesign in 2001. Before this they had a single CLS112-6 filter and housing just like on the Crown Victoria, located towards the rear of the vehicle. On the newer models they added a low pressure filter after the regulator up by the front of the vehicle. When I change these filters on my civics, I always find it interesting that there is more oil in the low pressure filter canister (I cut them open to check) than in the high pressure filter bowl.
            Last edited by NGXV; 01-31-2010, 02:10 AM.


            • #21
              Re: Service Bulletin concerning Crown Vic rough idle

              does anyoone know the part number for a 1998 cng crown vic filler neck?


              • #22
                Re: Service Bulletin concerning Crown Vic rough idle

                Two questions:
                1. The instruction on the PM-5 can says to dilute it with gasoline (2 pints of gasoline for 8 oz of PM-5). It also says "Do not inject undiluted PM-5 into the engine". Do I need to do this for my CNG Crown Vic?
                2. What kind of alcohol should I use and where can I buy it? I understand that I need very high concentration alcohol.
                Thanks for your help.


                • #23
                  Re: Service Bulletin concerning Crown Vic rough idle

                  Sorry to revive this thread... but I feel I need to do this on my '99 F250 (bifuel)..

                  Can anyone point me to a video to do this? A guy who inspected my tanks said you just are supposed to disconnect the power from the tanks, and then run the engine with rubbing alcohol somewhere... any ideas waht he was tlaking about?



                  • #24
                    Re: Service Bulletin concerning Crown Vic rough idle

                    Thanks so much for posing these TSBs! I'm having the same problem with mine so hopefully the shop will find this very valuable. Thanks again!!!


                    • #25
                      Re: Service Bulletin concerning Crown Vic rough idle

                      Thank you so much for posting this information! I have been so frustrated trying to figure out how to fix my lean bank codes misfire codes and oxingen sensor codes. I followed your directions and E 350 runs great now and the check engine light is off now, than you so much,


                      • #26
                        Re: Service Bulletin concerning Crown Vic rough idle

                        Perfect find!

                        I have just purchased a 2000 Crown Vic, factory CNG. The seller said it idled a bit rough when cold, and then ran great. It should be delivered in about a week.

                        Looks like I have found the fix!

                        I just purchased a Motorcraft filter from eBay.


                        • #27
                          Re: Service Bulletin concerning Crown Vic rough idle

                          My 2000 crown vic was also running rough at low RPM, the other day I was driving down the road and it just died on me in the middle of the road and would not restart. After some looking i found that it had blown the 20A #1 fuse in the power distribution box that is labeled to control the fuel pump. I believe it controls the fuel solenoid valves in the CNG version. Could this have been causing my rough idle as well? I followed the steps posted here about cleaning out the filter prior to all of this, but it was not dirty at all.

                          If I replace the fuse it immediately blows it again. Maybe the wire running back to the fuel tanks is grounding out somewhere, but could bad solenoids also cause this problem?