AEM 30-6905 Universal Programmable EMS-4 - Manual (Page 160)

Page 160 of 279 EMS-4 Install and Tuning Guide_Rev 1.6
Fuel Map Operating Areas
Every engine is different but in general the main fuel and ignition maps can be broken up into
areas of operation as shown above.
Idle – Where an engine spends 99% of its time.
Accel / Lugging – The area of the fuel map accessed briefly during snap accelerations. Also
the area used during lugging conditions in high gear.
Wide Open Throttle – Area accessed during wide open throttle operation.
Heavy Load Part Throttle – High load part throttle acceleration.
Cruise – Light load cruise conditions.
Decel / Over Run – High vacuum and high RPM condition. Generally accessed with vehicle in-
gear going downhill.
Fuel Trims
The EMS has many available trims for fuel. The following section will describe each.
IDLE
CRUISE
DECEL/OVER RUN
WIDE OPEN THROTTLE
ACCEL /
LUGGING
HEAVY LOAD PART THROTTLE