Low boost, high fuel consumption and 00561 fault

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • UrS4boy
    S2Forum Obsessed
    • Feb 2006
    • 11859
    • Country: Canada

    #31
    At least we agree that blocking the PCV outlet on the MAF turbo hose (at the location I labelled as [A3] in my AAN air flow diagram) is needed to prevent putting pressure backward through the PCV system.

    "Pressurizing any other way than plugging the MAF, blocking the PCV outlet on the MAF turbo hose and maybe pinching the wastegate hose is a complete waste of time"

    That is a good option too. I will revise my Option list to include it as "Option A4".
    RS2'd 93 UrS4 5 spd sedan
    94 UrS4 V8 6 spd manual avant

    Comment

    • prj
      S2Forum Zealot
      • Mar 2010
      • 6308
      • Country: Estonia

      #32
      Originally posted by UrS4boy
      At least we agree that blocking the PCV outlet on the MAF turbo hose (at the location I labelled as [A3] in my AAN air flow diagram) is needed to prevent putting pressure backward through the PCV system.
      Huh no. You only need to remove the hose from the MAF-Turbo hose, block the hole in the MAF-turbo hose, and leave the hose/pipe that comes from the cam cover to atmosphere.
      Under no circumstances should you block the hose/pipe that comes from the cam cover, unless you want a huge amount of blue smoke afterwards.

      That way the PCV system does not get pressurized at all, because it's vented to atmosphere.
      If you want to specifically test the PCV system, then after you are done with every thing else, put a minute amount of pressure in with the PCV system plumbed in as on a running car, maybe 0.1-0.2 bar. It's not supposed to hold any more than that.
      http://tuner.ee - http://www.facebook.com/tuner.ee

      Comment

      • UrS4boy
        S2Forum Obsessed
        • Feb 2006
        • 11859
        • Country: Canada

        #33
        Originally posted by prj
        Huh no. You only need to remove the hose from the MAF-Turbo hose, block the hole in the MAF-turbo hose, and leave the hose/pipe that comes from the cam cover to atmosphere. Under no circumstances should you block the hose/pipe that comes from the cam cover, unless you want a huge amount of blue smoke afterwards.
        Location [A3] *is* the hole in the MAF-turbo hose formerly connected to the cam cover port. So we agree on that.

        So given [A3] is plugged as above, let's say I follow your (good) suggestion that the cam cover vent hose/port remains unblocked and during the pressure test with the pressurizing bung at the MAF end of the MAF to turbo hose produces air flow out of the cam cover port, what is your conclusion? (It's a trick question).
        RS2'd 93 UrS4 5 spd sedan
        94 UrS4 V8 6 spd manual avant

        Comment

        • prj
          S2Forum Zealot
          • Mar 2010
          • 6308
          • Country: Estonia

          #34
          Originally posted by UrS4boy
          So given [A3] is plugged as above, let's say I follow your (good) suggestion that the cam cover vent hose/port remains unblocked and during the pressure test with the pressurizing bung at the MAF end of the MAF to turbo hose produces air flow out of the cam cover port, what is your conclusion? (It's a trick question).
          I already wrote before:
          Originally posted by prj
          The PCV system never gets pressurized this way. Ever. If everything you put in leaks out of the PCV then you know the one way valve under the manifold is shot.
          The only other reason would be a hole in one of your pistons.

          Some air is supposed to come out of there, as it leaks past the rings, but very little - a minute amount.
          The reason to decouple it from the intake is to prevent pressurizing the sump and having the oil rise up.
          http://tuner.ee - http://www.facebook.com/tuner.ee

          Comment

          • UrS4boy
            S2Forum Obsessed
            • Feb 2006
            • 11859
            • Country: Canada

            #35
            Originally posted by prj
            If everything you put in leaks out of the PCV then you know the one way valve under the manifold is shot
            Air or liquid will always find the path of least resistance to escape. If the one-way valve is stuck open, there will be a "boost" leak at a lower pressure (if you can even build *any* pressure) that won't open up a split in a boost hose (typically the AAN Michelin Man hose splits only open up at higher boost pressures). So before you are done, you first have to replace the one-way valve and then retest to find the other leaks.

            This is *NO* different than first isolating the boost hoses (eliminating the PCV system from the test) and pressurizing, finding the leak(s) and replacing the problem hoses/clamps/O-rings and then re-testing to find you still have a boost leak via the PCV system one-way valve.

            Boost testing is a multi-step/repeat process until there is no more (significant) leaks.

            Can we agree on that?
            RS2'd 93 UrS4 5 spd sedan
            94 UrS4 V8 6 spd manual avant

            Comment

            • prj
              S2Forum Zealot
              • Mar 2010
              • 6308
              • Country: Estonia

              #36
              Originally posted by UrS4boy
              Air or liquid will always find the path of least resistance to escape. If the one-way valve is stuck open, there will be a "boost" leak at a lower pressure (if you can even build *any* pressure) that won't open up a split in a boost hose (typically the AAN Michelin Man hose splits only open up at higher boost pressures). So before you are done, you first have to replace the one-way valve and then retest to find the other leaks.
              Or block it off, since it's useless.

              Boost testing is a multi-step/repeat process until there is no more (significant) leaks.
              Correct.

              Most people for some reason do not test the multitude of systems attached for the inlet manifold thus resulting in huge overtime during mapping process because the car does not make any boost and is pig rich.
              I flat out refuse to map anything before pressure testing it these days.
              http://tuner.ee - http://www.facebook.com/tuner.ee

              Comment

              • UrS4boy
                S2Forum Obsessed
                • Feb 2006
                • 11859
                • Country: Canada

                #37
                Originally posted by prj
                Most people for some reason do not test the multitude of systems attached for the inlet manifold thus resulting in huge overtime during mapping process because the car does not make any boost and is pig rich. I flat out refuse to map anything before pressure testing it these days.
                I understand your frustration. I will revise my boost testing option posts according (BUT I will still leave "options" - but with stronger recommendations for some options over others).
                RS2'd 93 UrS4 5 spd sedan
                94 UrS4 V8 6 spd manual avant

                Comment

                • LitD
                  S2Forum Buff
                  • Nov 2011
                  • 38
                  • Country: United Kingdom

                  #38
                  I took the Michelin Man hose today and other than being full of oil, there's nothing wrong with it that I can see, it actually looks pretty new. There is also no play in the turbo shaft. The saga continues.

                  Comment

                  • prj
                    S2Forum Zealot
                    • Mar 2010
                    • 6308
                    • Country: Estonia

                    #39
                    Have you pressure tested the car ?
                    Pulling off hoses is a waste of time.
                    http://tuner.ee - http://www.facebook.com/tuner.ee

                    Comment

                    • LitD
                      S2Forum Buff
                      • Nov 2011
                      • 38
                      • Country: United Kingdom

                      #40
                      Not if I can see hole in it it's not, bearing in mind I don't have a pressure testing kit to hand. Plus it was full of oil when I pulled it off, so I'd expect to see some oil spray from a hole if there was one.

                      Comment

                      • simon20vq
                        S2Forum Extremist
                        • Dec 2010
                        • 1379
                        • Country: United Kingdom

                        #41
                        I would check the temp sender on the back of the head and the o2 sensor.

                        Comment

                        • prj
                          S2Forum Zealot
                          • Mar 2010
                          • 6308
                          • Country: Estonia

                          #42
                          Originally posted by LitD
                          Not if I can see hole in it it's not, bearing in mind I don't have a pressure testing kit to hand. Plus it was full of oil when I pulled it off, so I'd expect to see some oil spray from a hole if there was one.
                          There are two options - you get a pressure test kit, or you sell/break the car.
                          There are a million places where it can leak from and you are never going to find it without a pressure tester.
                          http://tuner.ee - http://www.facebook.com/tuner.ee

                          Comment

                          • Rusty
                            Super Moderator
                            • Jun 2004
                            • 18953
                            • Country: United Kingdom

                            #43
                            ^^ ^^

                            You an make your own pressure tester using a pipe bung and car valve.
                            Cheers'en, AndyC
                            1994 ABY Coupe - Projekt Alpinweiss

                            Comment

                            • UrS4boy
                              S2Forum Obsessed
                              • Feb 2006
                              • 11859
                              • Country: Canada

                              #44
                              Originally posted by Rusty
                              You an make your own pressure tester using a pipe bung and car valve.
                              Something like this (this one has an air compressure hose connection but it could be a tire Schraeder valve instead).

                              RS2'd 93 UrS4 5 spd sedan
                              94 UrS4 V8 6 spd manual avant

                              Comment

                              • 5cylinderman
                                S2Forum Addict
                                • Oct 2011
                                • 367
                                • Country: Ireland

                                #45
                                Get a Schrader valve from your local tyre shop. Then buy a new oil filter that fits inside your MAF hose. Drill a hole in the end of the filter, pop in the valve and hey presto a ghetto boost leak tester.

                                Comment

                                Working...