High idle at warm

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  • DeS
    S2Forum Maniac
    • Feb 2004
    • 611
    • Country: Poland

    #16
    Originally posted by twoqu
    Well 215 would be 105 degrees and if the fan comes on at over 220 that would make it over 110 degrees. Usually tthe car should run at 88-90 degrees. So either it running very hot or there is indeed an issue with the temperature sensor for the Motronic.
    That make sens, because as far as I remember, few months ago, fan was starting just after 90'C on gauge, right know it start almost reaching first point (.) on temperature gauge. So maybe fan blows only at second stage (at 105'C) and first stage is missing?

    Will check coolant sensor tomorrow.

    Comment

    • twoqu
      S2Forum Possessed
      • Sep 2003
      • 3103

      #17
      Just read some old threads. So you are using AAN/ABY/ADU Motronic not 3B?

      Comment

      • DeS
        S2Forum Maniac
        • Feb 2004
        • 611
        • Country: Poland

        #18
        Its 3B.

        Coolant sender showed 890 ohms and it was very slowly rising. Engine was still warm after last warming up.

        Another thing I forgot to write, is right now every time I warm up to fan starting cooling down, afterrun cooling is switchin on. We have 10'C in Warsaw right know so it not so hot to after run must cool down the engine. I guess thats messeage that engine is heating over
        Last edited by DeS; 14 October 2013, 18:31.

        Comment

        • twoqu
          S2Forum Possessed
          • Sep 2003
          • 3103

          #19
          Is there more than 10L of fuel in the vehicle? I didn't believe it could sense this but once I added some more fuel the static 128 started to change! If you have more than 10L and it does not move then the Lambda is a suspect.
          I take it you have the 3B Motronic manual. You will have to look at the values and see which ones are close to outside thelimits and work through the solutions. Start with the ones that are outside and not due to the high idle.
          Frustrating but it makes sense to eliminate faults.
          Whether there is an issue with the SW/injectors is an unknown, unless that SW is designed to run those particular injectors.

          Comment

          • DeS
            S2Forum Maniac
            • Feb 2004
            • 611
            • Country: Poland

            #20
            Ok, so today I did some checking, plugs refitings, cleaning, brushing etc

            Here's how it looks today:




            Did the measure till the temperature hits 90'C+, not more:
            - engine load very nice
            - lamba has moved
            - engine speed not as required, but better and acceptable

            Don't know wats the problem, but I think is connected with MAF plug - it live its own life

            I've checked also fan wiring, and the fan starts on both stages when I short pins in plug. I'm waiting for new sensor in radiator.

            Cheers Guys for your advices.

            Comment

            • DeS
              S2Forum Maniac
              • Feb 2004
              • 611
              • Country: Poland

              #21
              I have to refresh.

              Temperature and fan problem has been solved.

              Issue with idle revs still can't let go.


              Today I've changed MAF to almost new RS2 one. Car's runinig in my opinion a little bit better, but after warm up still gets 1200 and even higher idle.

              I did some measurements of new MAF with connector pluged at idle it looks like it has same voltage like previous one. Between PIN 1 and 3 is showing 2.3-2.5 volts and sometimes gets lower to 2.0 volts.

              Right know only thing I have on my mind to see internal of ECU and check for electrical problem.

              HELP!

              Comment

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

                #22
                There is nothing wrong with your ECU.

                Replace engine coolant sensor (there are different sensors for clocks and engine iirc?).
                Also replace ISV.
                Verify that at idle the throttle is closed properly and that the idle switch engages correctly.
                Make a proper pressure test, pressurizing the intake manifold as well, if you have a vacuum leak somewhere, it will draw extra air and also cause high idle.

                After that your idle will be fine.
                http://tuner.ee - http://www.facebook.com/tuner.ee

                Comment

                • DeS
                  S2Forum Maniac
                  • Feb 2004
                  • 611
                  • Country: Poland

                  #23
                  I think I'm on a turning point.

                  Guy who gave me the software, has ohnest admited that propably this software has high idle function, because he had same problem with car this software belongs. He never solved that thinking it would be better for racing engine with higher oil presure etc.

                  I think i need another software

                  Comment

                  • filip.krticka
                    S2Forum Enthusiast
                    • Sep 2008
                    • 170
                    • Home: Czech Republic

                    #24
                    Originally posted by DeS
                    I think I'm on a turning point.

                    Guy who gave me the software, has ohnest admited that propably this software has high idle function, because he had same problem with car this software belongs. He never solved that thinking it would be better for racing engine with higher oil presure etc.

                    I think i need another software
                    Des,
                    it's well known on 3B engine and control unit upgraded to RS2 spec 360bhp.
                    I have the same "issue" I'm running on the similar type of software. It was originally made by MTM and stolen afterwards I guess. For some reason iddle speed is setup to 1100rpm and idle is rich as well.
                    Root cause is your software.

                    Cheers.

                    Comment

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

                      #25
                      Engine Coolant Temp Sensors - G62, F76 and climate control

                      Originally posted by prj
                      ...Replace engine coolant sensor (there are different sensors for clocks and engine iirc?).
                      There are at least two and maybe three engine coolant temp sensors.

                      The G62 Engine Coolant Temperature Sensor used by the ECU to determine whether the engine has warmed up or not (this is the one that could cause a high/rich idle issue if it fails):

                      The Audi Enthusiast website. Forums for all Audis including A4, S4, A5, S5, A6, S6, allroad, A8, S8, TT, R8, Q5, Q7, 4000, 100, 200, v6, v8, vintage, local forums


                      The F76 Multifunction Temperature Switch (MFTS) used to drive the coolant temperature gauge and for the 3B, ABY and ADU a signal to the ECU via Pin T55/46 re: over temperatures:

                      The Audi Enthusiast website. Forums for all Audis including A4, S4, A5, S5, A6, S6, allroad, A8, S8, TT, R8, Q5, Q7, 4000, 100, 200, v6, v8, vintage, local forums



                      The climate control temperature sensor for those vehicles equipped with the automatic climate control system:

                      The Audi Enthusiast website. Forums for all Audis including A4, S4, A5, S5, A6, S6, allroad, A8, S8, TT, R8, Q5, Q7, 4000, 100, 200, v6, v8, vintage, local forums


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

                      Comment

                      • DeS
                        S2Forum Maniac
                        • Feb 2004
                        • 611
                        • Country: Poland

                        #26
                        Originally posted by filip.krticka
                        Des,
                        it's well known on 3B engine and control unit upgraded to RS2 spec 360bhp.
                        I have the same "issue" I'm running on the similar type of software. It was originally made by MTM and stolen afterwards I guess. For some reason iddle speed is setup to 1100rpm and idle is rich as well.
                        Root cause is your software.

                        Cheers.

                        Just can't believe it. Whats the point seting idle so high? I see no reason

                        Maybe someone is using similar software without this kind of special seting?

                        Cheers!

                        Comment

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

                          #27
                          I can give you better software
                          http://tuner.ee - http://www.facebook.com/tuner.ee

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