Fuel trim

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  • paullap
    Member
    • Dec 2016
    • 64

    Fuel trim

    Hi I am a new Verus user, and I could do with some help please, when I go through the vehicle selection I've , vw,polo, 2005 , 1.4 BKY engine, I have a p1111 code, I go in to data, and I have no short term or long term fuel trim pids?. All I can see Is fuel adaption, it is at 24%. This car has a wide band 02 sensor , and I know it is difficult to test these, I have been trying sort this car for weeks now, I am getting black soot out of the exhaust.

    Paul
  • Crusty
    Senior Member
    • Dec 2007
    • 2450

    #2
    Hello there. If some of the Euro guys chime in I'm sure they could tell you more.
    I would bet the adaption 24% is your long-term fuel trim.
    High fuel adapt (more fuel) & black smoke out the tailpipe (more fuel).
    What would make it WANT more fuel (24%).
    If it had high fuel pressure causing the black smoke, it wouldn't want more.
    If it had a vacuum leak making it want to adjust to 24%, you wouldn't have the black smoke.
    It's getting too much fuel and it WANTS too much fuel.... WHY....
    My first suspicion is the airflow measurement (MAF sensor) thinking it's getting more air than it really is, or possibly coolant sensor telling it that it's cold and thus more fuel demanded.
    Check out NGK/NTK website for some good information regarding the various designs of oxygen sensors. Yes, it could be the Oxygen sensor but they can be checked out.
    If you write down all your codes and save your freeze-frame information, THEN clear the codes & fuel adaption, disconnect the O-2 sensor, then start it up, what does it do-?? It won't adjust the fuel up to 24% because it should set an O-2 code, but you could see what comes out the back. If you've still got black smoke (after it has a chance to clear itself out from sooting up) I'd be verifying the other things that can cause the black smoke.
    Adding something to your profile would let everyone know whether you're here in North America, or elsewhere. Australian vehicles and British vehicles are different than what we have here. I've never heard of a VW-Polo...
    Good luck and have fun with the wide-band sensor learning.

    Comment

    • Steve6911
      Moderator
      • Feb 2007
      • 2168

      #3
      Until you get a full grasp on how the system works go into Global OBDII and it will give you fuel trims as you understand them. Compare the Global readings to the Manufactures and you should be able to understand it better.


      Steve

      Comment

      • Witsend
        Banned
        • Nov 2012
        • 2942

        #4
        I find You Tube is a good place to look for information.Thought The Polo was a White Chevy Camaro with a red Trans Am Eagle decal on the hood .Good luck



        Last edited by Witsend; 07-18-2017, 07:04 AM.

        Comment

        • paullap
          Member
          • Dec 2016
          • 64

          #5
          Thanks for the help, so are we say , it always has short and long term trim , and not makers specific, I think I might be going in to the wrong section, I get to reading codes, clear them and then engine and data, is this where it should be, should it not be called live data?.

          Paul

          Comment

          • Steve6911
            Moderator
            • Feb 2007
            • 2168

            #6
            Hmmmm..... Being its a Polo, I'm guessing your on the other side of the pond not in the States, correct? do you have any form of Global OBDII on the scanner?

            Comment

            • paullap
              Member
              • Dec 2016
              • 64

              #7
              Fuel trim pids

              Yes I think you can go in to obd 11. I am not near my scanner for a few days, I am just trying to find out all I can, I am guessing all manufactures all have different pids, can you get the short and long term fuel trim through obd11 if it is not listed going through the scanner.

              Paul

              Comment

              • Steve6911
                Moderator
                • Feb 2007
                • 2168

                #8
                yes you can

                Comment

                • paullap
                  Member
                  • Dec 2016
                  • 64

                  #9
                  Hi Steve, thanks for the help, I will give it a go as soon as i can . If you are the other side of the pond, where are you ?.

                  Paul

                  Comment

                  • Witsend
                    Banned
                    • Nov 2012
                    • 2942

                    #10
                    Probably State side converting Camaro's into White Trans Ams with Polo decals on the hoods

                    Comment

                    • kirkbarrow.garage
                      Senior Member
                      • Jan 2015
                      • 149

                      #11
                      Originally posted by Crusty
                      Hello there. If some of the Euro guys chime in I'm sure they could tell you more.
                      I would bet the adaption 24% is your long-term fuel trim.
                      High fuel adapt (more fuel) & black smoke out the tailpipe (more fuel).
                      What would make it WANT more fuel (24%).
                      If it had high fuel pressure causing the black smoke, it wouldn't want more.
                      If it had a vacuum leak making it want to adjust to 24%, you wouldn't have the black smoke.
                      It's getting too much fuel and it WANTS too much fuel.... WHY....
                      My first suspicion is the airflow measurement (MAF sensor) thinking it's getting more air than it really is, or possibly coolant sensor telling it that it's cold and thus more fuel demanded.
                      Check out NGK/NTK website for some good information regarding the various designs of oxygen sensors. Yes, it could be the Oxygen sensor but they can be checked out.
                      If you write down all your codes and save your freeze-frame information, THEN clear the codes & fuel adaption, disconnect the O-2 sensor, then start it up, what does it do-?? It won't adjust the fuel up to 24% because it should set an O-2 code, but you could see what comes out the back. If you've still got black smoke (after it has a chance to clear itself out from sooting up) I'd be verifying the other things that can cause the black smoke.
                      Adding something to your profile would let everyone know whether you're here in North America, or elsewhere. Australian vehicles and British vehicles are different than what we have here. I've never heard of a VW-Polo...
                      Good luck and have fun with the wide-band sensor learning.
                      Hi, a Volkswagen Polo used to be sold in the USA 🇺🇸 as the Fox, in the same era that the Golf was called the Rabbit.
                      However the Fox did become a trim in the Polo range in Europe later on too 😇😇
                      Hopefully this helps 😎😎😎

                      Comment

                      • David Green
                        Senior Member
                        • Oct 2009
                        • 382

                        #12
                        Originally posted by paullap
                        Hi I am a new Verus user, and I could do with some help please, when I go through the vehicle selection I've , vw,polo, 2005 , 1.4 BKY engine, I have a p1111 code, I go in to data, and I have no short term or long term fuel trim pids?. All I can see Is fuel adaption, it is at 24%. This car has a wide band 02 sensor , and I know it is difficult to test these, I have been trying sort this car for weeks now, I am getting black soot out of the exhaust.

                        Paul
                        Always start the diagnosis with an understanding of what the fault code represents, in your case a lean condition, which means that because the oxygen sensor is sensing an excess of oxygen then the signal being sent to the PCM is advising the PCM to enrich the fuel supply to accommodate for the air leak.

                        Comment

                        • Witsend
                          Banned
                          • Nov 2012
                          • 2942

                          #13
                          Always start the diagnosis with an understanding of what the fault code represents, in your case a lean condition, which means that because the oxygen sensor is sensing an excess of oxygen then the signal being sent to the PCM is advising the PCM to enrich the fuel supply to accommodate for the air leak.
                          I say if he can't figure out that VW in weeks already , refer to Sure Crak spin the EEC pin wheel, and start with swapping out the purge flow valve.
                          Attached Files
                          Last edited by Witsend; 08-01-2017, 07:49 PM.

                          Comment

                          • paullap
                            Member
                            • Dec 2016
                            • 64

                            #14
                            P1111

                            Thanks for the help, I am sure it is a air leak, I just cant find it. Can I just block of the purg valve?. To eliminate the complete evap system?. I have tried a smoke test, with just smoke from a smoke machine, but I think I might need a bit of air pressure to push the smoke out of the leak. My verus only gives me fuel adoption, not short and long term trim, Is this correct?. warmed up at idle 24% and I have a feeling it is maxed out at that. this might give you a clue.

                            at tick over 24%
                            at about 3/4 throttle 24%

                            if i keep snapping the throttle it goes to 0% and minus figures

                            as soon as it settles down at idle it goes back to 24%

                            Comment

                            • Witsend
                              Banned
                              • Nov 2012
                              • 2942

                              #15
                              Sure , you can Unplug the evap purge valve electrical connector and in the deenergized state the evap purge valve should normally be closed and no air should be passing through it and no engine vacuum shouldn't be felt passing through on the other end if you pull the hose/tube off on the evap system end of the evap purge valve at idle if you have the electrical connector unplugged. I would think you would eventually set an evap system leak code if that were the case. See if it has any pending codes before you try it. Watch the fuel trims at idle while you deny the vacuum supply to things like egr , brake booster, evap purge, pcv etc. you can Spray carb cleaner or use propane, or smoke to check for vacuum leaks.
                              Last edited by Witsend; 08-01-2017, 10:43 PM.

                              Comment

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