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E85, water vapor and dead O2 sensors.

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  • E85, water vapor and dead O2 sensors.

    At start up, the racecar's exhaust is water saturated. Wets the garage floor. It clears up as the engine heats up. I've been trying to use the LM-1 to tune the initial start-up but the sensors die. The LM-1 begins to show a richer and richer mixture unitl it simply says "too rich" and then gives me the Error 04 message. Reading Innovative's forum, Klaus states that excess water vapor will kill the sensor. Does anyone else have this problem?

    Should I only turn the LM-1 on after engine warm-up, after the water vapor has abated? If so, can someone suggest a tuning regimen that I can use, absent an AFR gauge, to help me tune in the initial start-up?

    Thanks for the help.


  • #2
    Re: E85, water vapor and dead O2 sensors.

    Water vapor in all forms kills O2 sensors, that's the reason they mount them horizontally instead of vertically (keeps the condensation risk down) they also need a certain amount of heat to operate properly too, which is why most (probably all now) have some kind of heating setup (I imagine the heat also helps burn off any residual condensation, but that's just supposition on my part). I don't know how yours is setup but that's the first two things I'd check, proper sensor mounting and if you have the heater hooked up. Most FI uses what's called an open-loop mode until the engine is properly warmed up. Simply put, the ECU won't even poll the O2 sensor until the coolant temp reaches a certain point. So assuming I'm understanding the question correctly, wait until your engine is up to proper operating temp. before switching it on (though you really shouldn't have to switch it on if everything is installed correctly).


    • #3
      Re: E85, water vapor and dead O2 sensors.

      Its an aftermarket AFR gauge using a Bosch 5 wire O2 sensor. The ECU is a Haltech aftermarket programmable stand alone. The sensor has an integral heater. The sensor is mounted at a 90 degree angle to the tubing wall. Its located after the turbocharger in a downpipe section of the exhaust. The pipe is essentially vertical to the ground plane, so any water condensation would run down to the 90* degree bend to the horizontal exhaust.

      As it is currently hooked up, the LM-1 (aftermarket AFR) comes on as soon as I turn on the master power switch. So there is the potential of having the sensor heated prior to the engine start-up. That would be bad. Maybe I need to rewire it so that it does not come on until its commanded to do so.



      • #4
        Re: E85, water vapor and dead O2 sensors.

        From the LM-1 manual (I'm sure you have it and have read it, but just in case it was a CL or ebay find)

        It is NOT a good idea to connect the LM-1 permanently to 12V and switch it on before the vehicle
        is started. Depending on the climate and the sensor position in the exhaust, condensation water
        can form in the exhaust pipes. This condensation water could then be blown by the exhaust
        stream against the hot sensor when the car is started. The resulting heat shock can permanently
        damage the sensor.
        To protect the LM-1 when installed permanently it is a good idea to power the LM-1 only after
        the car is started. The starter motor in some vehicles can create voltage spikes of over 100V
        that have the potential to do damage. Although rare, this is a real possibility and the LM-1
        contains protection circuitry to guard against it.
        There's more, but you get the idea.

        When in doubt, go back and reread all the manuals...

        LM-1 manual:

        Haltech (not sure which one of the millions you have):

        Bosch (more than you ever wanted to know, really):

        Hopefully something somewhere in there can get you on the road to happiness again.


        • #5
          Re: E85, water vapor and dead O2 sensors.

          Thanks a bunch. I really like the Bosch site. Any idea how one would go about testing a sensor, Bosch references using a DVOM but doesn't give the procedure. I'll have to do some searching.



          • #6
            Re: E85, water vapor and dead O2 sensors.

            You cannot properly test an O2 for output with just a digital DVOM. It MUST be able to graph like a lab scope. (voltage over time)

            A digital readout simply will not show any irregularities of the signal that a graphed display does. Anybody that tells you different is incorrect.

            I use a Snap-On Vantage to test them here.

            Chris 8)


            • #7
              Re: E85, water vapor and dead O2 sensors.

              Thanks. I went ahead and bought another sensor.