AEM 30-6905 Universal Programmable EMS-4 User Manual
Page 181
Page 181 of 279 EMS-4 Install and Tuning Guide_Rev 1.6
based trim to accel fuel because a cold engine will need more accel fuel compensation
than a warm engine.
To recap what's happened, a filtered throttle position change has been detected and from this
value, a base % accel pump was determined. Then it was corrected for TPS, RPM and Coolant
temperature.
Now, it is checked against the user option Accel Limit. If it is larger than this value, then it is
reset to this value. This percentage is multiplied by the current injector PW, giving a time in uS,
and is applied as the starting value for the accelerator pump.
Once the pump is applied, the EMS decreases the pump size to zero, assumingthere are no
more accel pump actions in the meantime. This is controlled with the Accel Pump Sustain
option. On a fixed time basis, the EMS comes back, andmultiplies the current value of the
pump by the decay percentage, yielding the new, decayed pump. Thus, a larger value
makes the pump decay slower.
Accel Fuel Channels