Poorly S4...again.

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • hunker7
    S2Forum Possessed
    • Mar 2014
    • 3487
    • Home: Latvia Current: United Kingdom

    #1

    Poorly S4...again.

    My forever ****** running S4 isn't running right again. Don't really know what to look for anymore, no error codes and I've chnaged all sorts including lambda and maf sensors. Checked compression as well that's all good too. Just feels very flat? Boost is there but just doesn't have the go. I have 2 liter diesel Beemers flying past me as if I'm stationery?

    anyone down south would want to look at her maybe?

    cheers lads
    '93 Audi 100 Avant - R.I.P
    '92 Audi UrS4 Avant - SOLD
    '93 Audi UrS4 Avant
    '15 Audi A7 quattro 3.0 TDI
  • Colesy
    S2Forum Fiend
    • Feb 2009
    • 2982
    • Country: England

    #2
    Boost leak or iffy MAF plug? Mine currently eevry week or two starts running flat with no go at all. All I do is unplug the MAF and plug it back in which immediately fixes it. Need to get around to changing the MAF pins...

    Hope it's an easy fix

    Comment

    • hunker7
      S2Forum Possessed
      • Mar 2014
      • 3487
      • Home: Latvia Current: United Kingdom

      #3
      Done a boost test and no leaks, I've checked mad plug and there is no corrosion on any of the pins. Tested MAF plug using Dave's (UrS4boy) procedure and it was all well within spec.
      '93 Audi 100 Avant - R.I.P
      '92 Audi UrS4 Avant - SOLD
      '93 Audi UrS4 Avant
      '15 Audi A7 quattro 3.0 TDI

      Comment

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

        #4
        Originally posted by hunker7
        Done a boost test and no leaks, I've checked mad plug and there is no corrosion on any of the pins. Tested MAF plug using Dave's (UrS4boy) procedure and it was all well within spec.
        Do you have a boost gauge? What level of max boost are you getting? Sounds to me like your issue is with the Moisture Trap on the firewall.
        RS2'd 93 UrS4 5 spd sedan
        94 UrS4 V8 6 spd manual avant

        Comment

        • hunker7
          S2Forum Possessed
          • Mar 2014
          • 3487
          • Home: Latvia Current: United Kingdom

          #5
          I do, I'll hook it back up and double check, last time it was good.

          I've connected it by the ECU with a t piece.
          '93 Audi 100 Avant - R.I.P
          '92 Audi UrS4 Avant - SOLD
          '93 Audi UrS4 Avant
          '15 Audi A7 quattro 3.0 TDI

          Comment

          • newsh
            S2Forum Obsessed
            • Aug 2003
            • 16226
            • Country: United Kingdom

            #6
            Yes check max boost pressure, if it’s only 0,4 Bar then either the ECU is not allowing boost control or the WGFV is not working.

            S2 Coupe 3B Project


            Ur quattro restoration

            S2 Avant

            Boost is the new rock and roll!
            sigpic

            Comment

            • newsh
              S2Forum Obsessed
              • Aug 2003
              • 16226
              • Country: United Kingdom

              #7
              Years ago I had same on my coupe, the WGFV was not fully plugged in!

              S2 Coupe 3B Project


              Ur quattro restoration

              S2 Avant

              Boost is the new rock and roll!
              sigpic

              Comment

              • hunker7
                S2Forum Possessed
                • Mar 2014
                • 3487
                • Home: Latvia Current: United Kingdom

                #8
                On the dash it goes to 2.3bar but is a little slow (I think) to get to it. I'll connect manual boost gauge back up and see.
                '93 Audi 100 Avant - R.I.P
                '92 Audi UrS4 Avant - SOLD
                '93 Audi UrS4 Avant
                '15 Audi A7 quattro 3.0 TDI

                Comment

                • Error404
                  Super Moderator
                  • Mar 2007
                  • 19789
                  • Country: United Kingdom

                  #9
                  Did you change the knock sensors?
                  Panthero Coupé quattro 20vt
                  Indigo ABY coupé
                  Imola B6 S4 Avant

                  Comment

                  • hunker7
                    S2Forum Possessed
                    • Mar 2014
                    • 3487
                    • Home: Latvia Current: United Kingdom

                    #10
                    Boost gauge shows 1.2/1.3 bar.

                    knock sensors have been done since I got the car 2 years ago, 1 is genuine and one was Siemens VDO.
                    '93 Audi 100 Avant - R.I.P
                    '92 Audi UrS4 Avant - SOLD
                    '93 Audi UrS4 Avant
                    '15 Audi A7 quattro 3.0 TDI

                    Comment

                    • hunker7
                      S2Forum Possessed
                      • Mar 2014
                      • 3487
                      • Home: Latvia Current: United Kingdom

                      #11
                      On my way back from work seemed like she's running right and then other times just sluggish and just not fun at all.
                      '93 Audi 100 Avant - R.I.P
                      '92 Audi UrS4 Avant - SOLD
                      '93 Audi UrS4 Avant
                      '15 Audi A7 quattro 3.0 TDI

                      Comment

                      • Error404
                        Super Moderator
                        • Mar 2007
                        • 19789
                        • Country: United Kingdom

                        #12
                        Replaced with new or just replaced with randoms?
                        Panthero Coupé quattro 20vt
                        Indigo ABY coupé
                        Imola B6 S4 Avant

                        Comment

                        • hunker7
                          S2Forum Possessed
                          • Mar 2014
                          • 3487
                          • Home: Latvia Current: United Kingdom

                          #13
                          Brand new, both.
                          '93 Audi 100 Avant - R.I.P
                          '92 Audi UrS4 Avant - SOLD
                          '93 Audi UrS4 Avant
                          '15 Audi A7 quattro 3.0 TDI

                          Comment

                          • hunker7
                            S2Forum Possessed
                            • Mar 2014
                            • 3487
                            • Home: Latvia Current: United Kingdom

                            #14
                            I've put new N75 H version on Colesy's group buy as that is one of the rare sensors I haven't done yet and heard people say it improves things if it hasn't been done and mine has down 220k miles
                            '93 Audi 100 Avant - R.I.P
                            '92 Audi UrS4 Avant - SOLD
                            '93 Audi UrS4 Avant
                            '15 Audi A7 quattro 3.0 TDI

                            Comment

                            • John.
                              S2Forum Fiend
                              • May 2012
                              • 2615
                              • Country: Scotland

                              #15
                              Choked/blocked exhaust maybe? Irregular fuel pressure?

                              Comment

                              Working...