5.3 Ignition settings 5 SETTING UP A BASIC CONFIGURATION
• Timing for Fixed Advance - only applies when "Fixed Timing" is set above. Timing is then locked to this
specified value.
• Cranking dwell - specifies the base coil dwell time during cranking before battery correction is applied.
• Cranking advance - The MS3Pro uses a fixed timing angle while cranking, specified here.
• Toyota Multiplex - Used for Toyota DLI distributorless ignitions. Known applications include the 7M-GTE
and Japanese market 4A-GZE. This uses the primary spark output as a timing signal, and secondary spark
outputs to specify which coil is active.
• Dwell type - Can be "Standard Dwell", "Fixed Duty", "Time after Spark", "Charge at Trigger" to accommodate
different ignition types.
– Standard Dwell - this is the setting to use for most installs. i.e. regular coils that are fired by a module
or with internal drivers or logic-level COPs. This is also used with GM-HEI7 and GM-DIS.
– Fixed Duty - locks the spark output to a constant duty cycle instead of controlling dwell. This is typically
used for ignition modules that control the dwell directly, including Ford’s "Push Start" TFI modules, Bosch
"smart" ignition modules, or MSD and other capacitive discharge boxes.
– Time After Spark - only intended for Saab Tri-Ionic DI cassettes that require a backwards dwell signal.
– Charge at trigger - This is a highly specialized mode intended for driving a CDI thyristor directly. Do not
use with multi-tooth wheels. Do not use with direct coil control or COP type ignitions as the dwell varies
with rpm and advance. Do not use if you are not certain what a thyristor is.
• Use dwell vs rpm curve - For Saab Tri-ionic and time-after-spark, the dwell can be varied with rpm.
• Use Dwell Table - Enables a 3D table of dwell as a function of RPM and load. This lets you run a low dwell
under vacuum and increase dwell only under boost, to reduce heat load on the coils.
• Nominal dwell - The base dwell time before battery voltage correction. (With the standard correction curve,
this time is applied at 14V.) Typical values are 3-4 ms.
• Spark duration - The time required for the spark to complete, typically in the order of 1 millisecond. Note
that in older single-coil systems with many cylinders, the dwell time can be constrained at higher rpm as there
isn’t enough time between cylinders for the desired dwell and spark. The dwell time is automatically reduced
in this case (this is the reason for stock HEI ignition being weak above 5000 rpm on V8s.) With wasted-spark
or COP, there is far greater time between ignition events and this dwell-reduction rarely occurs.
• Dwell time - the backwards dwell time for Time-After-Spark
• Dwell duty - for fixed duty, this specifies the percentage duty cycle of the output signal.
• Spark Hardware Latency - all electronic devices take a finite time to propagate signals and switch. This
setting allows for that slight delay. If you notice a slight retarding of ignition timing with rpm while strobing
with fixed timing, you can enter a small number in here to remedy it.
• Middle LED indicator - not used on MS3Pro.
• Spark Trim - enables the adjustment of timing per individual cylinder. This requires a suitable trigger wheel
capable of cylinder identification; modes like Basic Trigger do not allow this.
• Kick-start crank delay - For small engines with a kick starter, it can help to force a longer wait time on
cranking. This mode will delay starting if using basic trigger with a trigger angle of less than 20 degrees, or
trigger return mode, for the amount of time set by “Delay (ms)” underneath. Most other modes require the
ECU to detect a larger number of pulses, which results in a built-in delay.
Now, for the settings for specific ignition modes. Note that many of the model specific modes are named after one
common application of the settings, but there are often other engines that will use the same settings. For example,
the “4G63” mode is not just used on the Mitsubishi 4G63, but also on other Mitsubishi engines and Mazda Miatas.
AMP EFI MS3Pro manual version 1.202, firmware 1.5.0, 4/21/2017 Page 59
To Next Page
Loading...