MoTeC PLM - Manual (Page 11)

MoTeC Meter Operation 11
maximum power and at light loads the engine is tuned for emissions or
economy.
The following table gives a guide to the required Lambda values for different
tuning objectives.
Objective Lambda
Power 0.84 to 0.90
Economy 1.05
Emissions 1.00
Note: The exact requirements for a specific engine and fuel must be found by
experimentation.
Note: On Turbo Engines extra fuel may be desirable to reduce exhaust
temperatures and help avoid knock.
Note If the vehicle is fitted with a catalytic converter extra fuel may be required
to ensure the catalyst does not overheat when not operating at Lambda
1.00
Operating Tips
If the Engine misfires for any reason, including an over-rich mixture, the Meter
may falsely read Lean. This is due to excess air being present in the exhaust
gasses which is caused by incomplete combustion when the engine misfires.
Other areas that can give misleading readings include at high RPM, closed
throttle when the mixture won’t burn completely. Following overrun fuel cut the
sensor will become saturated with oxygen and can take up to several seconds
to resume accurate readings. Engine misfires include hitting the rev-limiter, be it
a fuel or ignition cut or a combination of both, and can give a similar result with
time being required to purge the sensor of excess oxygen or fuel.
Engines with high overlap camshafts running at low speed may pump air
through the engine resulting in a false lean reading, therefore the meter may
need to read leaner than would otherwise be expected.