Haltech F9A - Manual (Page 56)

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correction. For example, if an engine is tuned at sea level but is intended to be used mainly at
a higher altitude, then the reset should be performed once it reaches its new regular location.
After that, the automatic reading done at start up will be sufficient.
The third, F9A only, form of Barometric Correction is performed using a separate Barometric
pressure sensor. With a 1 Bar MAP Sensor (left open to atmospheric pressure) connected to
the Spare Input, any changes in barometric pressure can be compensated for immediately.
This is necessary when a large change in altitude is expected during a driving period (a Hill
Climb event such as Pikes Peak in the USA is a good example).
8.4 Post Start Enrichment
On some motors, in particular rotaries there is a problem with vapour-lock (fuel which due to
heating of the fuel rail has vaporised). The additional fuel at start up allows the vapour in the
fuel rail to be purged through the injectors and also allow enough fuel to be injected into the
motor to allow stable operation. Post start can also be used to give extra enrichment when the
engine is cold to assist drivability.
The Post Start Map is accessed via the Maps menu. It covers a time of sixty seconds with
each bar corresponding to 4 seconds of time. The time starts after the first input trigger is
received.
Two extra parameters are adjustable. The first is the Temperature setting and the second
indicates whether it operates Above or Below the Temperature setting. As an example, for a
rotary the temperature setting could be set at (say) 60°C (to indicate that the motor is warm or
has been running) and the operation setting to Above. This means that Post Start will operate
only when the coolant temperature is above 60°C.
When operation Above is selected, the enrichment only operates at idle. For below settings,
though, the enrichment operates at all throttle positions.