No announcement yet.

stalling issue

  • Filter
  • Time
  • Show
Clear All
new posts

  • stalling issue

    Hi Guys, Whenever I have the AC on and come out of gear to a rolling stop the RPM's drop low enough to cause stalling. Only happens if I come out of 2nd or 3rd gear and neutral roll to a stop, but If I downshift through the gears it will not stall obviously because the downshifts help keep the car engine on.
    Also noticed from time to time whether ac is On or Off the rpm gauge is so slightly erratic. FYI New plugs, new temp sensor.
    any help is appreciated. Thanks!

  • #2
    Sounds like a IACV issue?
    1988 M3
    2007 Lotus Exige S


    • #3
      where can I get one?


      • #4
        It's a fairly expensive part today, ~$400 so I'm not sure I'd just replace it without some diagnosis. Also certain failure modes of the IACV can also damage the drivers in the ECU.
        I deleted mine when I went alpha-n and didn't feel too bad about it as the DTM oil pan and engine mounts meant I deleted the AC compressor too. I did ship my used IACV to my brother as he was exhibiting similar stalling issues as you. I haven't heard anything since so I presume it may have fixed it...

        1988 M3
        2007 Lotus Exige S


        • #5

          Not that expensive...


          • #6
            I think if you have not already I would just cover off all the basic maintenance and tuning.
            Spark plugs, check HT leads and cap, then look over the intake hoses and check the adjustment of the throttle plates.
            Clean around the throttle plates with a toothbrush and some ATF oil.

            I think I would replace or at a minimum check the adjustment of the throttle switch just incase it is not always giving an idle signal for the ICV.
            Hopefully his may lead on to what is causing it and eliminate a few possibilities.

            E30 M3 1987
            Mini Clubman GT
            BMW E36 323 Msport
            Toyota Corona
            KTM 200EXC
            Honda CB50 (1979)


            • #7
              Make sure the idle contact inside the throttle position switch actually closes when foot off the throttle pedal.
              Irrespective of a/c on or off, does the engine resume injecting fuel around 1200 rpm when coasting from a higher rpm and foot off the throttle pedal (engine at operating temperature)?

              Does the i(A)CV buzz when ignition on and engine off? It should.

              What is your idle rpm? 880+/-50rpm is the spec.

              Can you drive off from standstill with just carefully letting the clutch out and not touching the throttle pedal with A/C off and engine warm or will it stall? It shouldn't but of it does it points to the icv being stuck or broken.


              • #8
                Do you get the +100RPM when you engage the AC button? The revs at idle should increase when the AC is engaged.



                • #9
                  Haven't had a chance to get the car out, but as soon as I have time to do so I will reply back to some of the suggested tips. I did order a new IACV, Price wasn't bad so why not.


                  • #10
                    FYI.. part came in within a week. pretty quick considering from Germany