OMEM710 Hardware Manual 2v11
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Start Fuel Throttle Table – This is the amount of fuel injected in cranking, dependent on throttle
position, while the engine is starting. This value is VE (same as the main fuel map) so is multiplied
by Microsec/bit to give the fuel pulsewidth.
Start Fuel Coolant Table – Extra percentage of fuel added to the Start Fuel Throttle due to
temperature.
Start Fuel Decay Table – This determines how quickly the additional start fuel decays over time.
This is a linear decay in seconds after cranking commences.
Start Fuel Pulse Table- This is an extra single injection of fuel that is injected at the very start of
cranking. This value is VE (same as the main fuel map) so is multiplied by Microsec/bit to give the
fuel pulsewidth.
Setting-up start fuel
It is important to note that the Coolant Fuel Trim table is always active, even under cranking
conditions, and so the cold engine running must be completed before the cold starting can be fully
calibrated.
The Start Fuel Throttle table very rarely requires changing from Omex’s standard values. The
standard values have 0 fuel at 100% throttle, allowing a flooded engine to be cleared by using full
throttle whilst cranking.
In general, an engine that has too much starting fuel will start and then immediately stop again. If
there is a very large excess of fuel, the engine may even ‘kick back’ as if it were too far advanced on
the ignition. An engine with too little starting fuel will crank for a long time before the engine will start.
Both of these situations call for a change to both the Start Fuel Pulse table, and the Start Fuel
Coolant table. If the engine starts but will not rev freely for the first few seconds of engine running,
then the Start Fuel Decay table usually requires adjusting.
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