Alfano Lambda Issue

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Permalink Reply by Simon Lewinson on December 13, 2011 at 17:29

Max, this could be anything - a broken wire or a clagged up sensor. These lambda probes are not designed for 2 stroke applications and get fouled up easily.

The sensor output can be measured and will be between 0.7 and 1.1 volts with the engine running and under load depending on the mixture.

Testing the sensor is easy with a small butane torch. Heat up the probe tip until it is red hot, then turn down the flame quite low. Move the sensor tip in and out of the flame and the display should change rapidly from rich at the base of the flame to lean out past the flame tip.

If the response is slow you can try cleaning the sensor. This is not supposed to be done but I have used the following process with good results.

• Make sure the exhaust is cold to the touch.
• Remove the sensor from the exhaust and gently brush off loose carbon with a soft toothbrush.
• Spray the sensor liberally with aerosol brake cleaner and continue to brush gently with the toothbrush.
  **** CAUTION **** this stuff is toxic and extremely flammable
• Once reasonably clean, connect the sensor up and fire up your butane torch.
  **** Make sure that there is nothing flammable in the area ****
• Burn off the deposits with a fairly large flame - the probe tip will start to glow red.
• Turn down the flame to low and move the probe in and out of the flame. If all goes well you should see rapid response to the movement on your easitune or alfano.
• When the probe cools it should be a nice tan colour, just like your spark plug.
• Reinstall and do not over tighten it.

Regards

Simon 

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Permalink Reply by Steve Southwell on December 13, 2011 at 20:22

Have had sensors fail at first use.

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Permalink Reply by mick triantafillidis on December 13, 2011 at 20:33

simple. use the easi tune sensor and lead.

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Permalink Reply by Steve O'Neil on December 13, 2011 at 20:43

Simon, this may well work, but does it affect the calibration of the sensor. After cleaning, does it return the same figures as a new or near new sensor?

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Permalink Reply by Simon Lewinson on December 14, 2011 at 7:36

Steve, as far as I know the "calibration" of a lambda sensor depends upon the design and materials used.

The most common issues with them are:

• poisoning by lead (appears rusty)
• silicon / silicate fouling (appears shiny white / grey)
• soot buildup
• oil fouling

The last two are our main issues and can be fixed by the judicious application of solvent and heat.

The manufacturers do not suggest this method of cleaning but there are numerous repoprts that it works fine.

I have just done this to two sensors that were heavily fouled and did not respond at all, now they respond immediately.

It would be an interesting exercise to compare a new sensor to one that had just been cleaned.

Simon

 

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Permalink Reply by Max Benson 26 on December 16, 2011 at 15:07

Hi mick, could that connect to my Alfano?
 
mick triantafillidis said:

simple. use the easi tune sensor and lead.

 

And thanks to everyone for replying :)

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Permalink Reply by Max Benson 26 on December 16, 2011 at 18:39

Hey simon, ill give it a go

Thanks alot
 
Simon Lewinson said:

Max, this could be anything - a broken wire or a clagged up sensor. These lambda probes are not designed for 2 stroke applications and get fouled up easily.

The sensor output can be measured and will be between 0.7 and 1.1 volts with the engine running and under load depending on the mixture.

Testing the sensor is easy with a small butane torch. Heat up the probe tip until it is red hot, then turn down the flame quite low. Move the sensor tip in and out of the flame and the display should change rapidly from rich at the base of the flame to lean out past the flame tip.

If the response is slow you can try cleaning the sensor. This is not supposed to be done but I have used the following process with good results.

• Make sure the exhaust is cold to the touch.
• Remove the sensor from the exhaust and gently brush off loose carbon with a soft toothbrush.
• Spray the sensor liberally with aerosol brake cleaner and continue to brush gently with the toothbrush.
  **** CAUTION **** this stuff is toxic and extremely flammable
• Once reasonably clean, connect the sensor up and fire up your butane torch.
  **** Make sure that there is nothing flammable in the area ****
• Burn off the deposits with a fairly large flame - the probe tip will start to glow red.
• Turn down the flame to low and move the probe in and out of the flame. If all goes well you should see rapid response to the movement on your easitune or alfano.
• When the probe cools it should be a nice tan colour, just like your spark plug.
• Reinstall and do not over tighten it.

Regards

Simon 

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Permalink Reply by Simon Lewinson on December 16, 2011 at 19:02

Max, please let me know how it goes.

regards

Simon

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