XMS3 TECHNICAL MANUAL

Perfect Power Online Manuals.

 

Support for your XMS3 Unit.

SPECIAL MAP

 

XMS3/XMS-L Stand Alone Unit - XMSV3 Icon The SPECIAL SCREEN contains:

XMS3/XMS-L Stand Alone Unit - Special Screen

SPECIAL INPUT

 

This input, and it associated mapping, is not used at present. This input can affect fuel or ignition.

 

 

INJECTOR TRIM (XMSV3 ONLY)

 

XMS3/XMS-L Stand Alone Unit - XMSV3 Icon

 

The 8-injector outputs can be trimmed individually by entering a value in the range 0.500 to 2.000. A value of 1.000 does nothing.


Injector trimming is called for if the manifold airflow is different to the various cylinders. It is also used for compensating for bad injectors, but this should not be attempted.

To find the airflow variations, or to check for the need to use the injector trim function, the EGT is measured for each cylinder. Then the fuel is reduced for the cylinders with the lowest EGT, or increased for the highest EGT, until all cylinders have the same EGT. This procedure is normally done at full throttle around 3000 RPM.

 

 

REQUIREMENTS

 

SEQUENTIAL INJECTION (CAM INPUT)
A VALUE OTHER THAN 1.000 ENTERED IN THE TRIM TABLE

 

 

IDLE FUEL UP (XMSV3 ONLY)

 

 

XMS3/XMS-L Stand Alone Unit - XMSV3 Icon

 

The purpose of this feature is to MOMENTARY increase the fuel in response to an external signal (SW#3).

The feature can be enabled, and then the switch input #3, pin 9-24 activates the feature.

 

At the closure of the switch (input), the IDLE UP FUEL is added to the injection, and then the added fuel value is depleted to zero in the next few seconds. This causes the engine to go rich for a second or so, until the IDLE MOTOR CONTROL LOOP re-acts.


The IDLE UP feature is used for transient loads such as:

 

  • AIR CONDITIONERS
  • ENGAGING AUTOMATIC TRANSMISSION


It helps the engine to cope with the load until the idle motor control loop “catches” the RPM and provides more air and fuel.

 

 

REQUIREMENTS

 

IDLE UP ENABLE: Tick
IDLE UP FUEL: >ZERO
OPEN to CLOSE INPUT CHANGE ON SW#3 INPUT

 

 

GEAR CHANGE FUEL CUT (XMSV3 ONLY)

 

XMS3/XMS-L Stand Alone Unit - XMSV3 Icon

 

This feature uses SWITCH #3 input, pin 9-24. As long as the switch is closed, the fuel is cut. This allows the racing driver to change gears without taking his foot of the throttle. It also helps a turbo engine and prevents “stalling” the turbo during throttle closure.

 

 

REQUIREMENTS

 

GEAR CHANGE FUEL CUT: Tick
A CLOSED SWITCH (LOW INPUT) on SW#3