boosted engines will continue to climb quite rapidly. After a specified number of RPM, the coil current is
cut in half. This will cause the engine to misfire and further reduce the RPM increase. If the engine
continues to climb, after the second specified number of RPM, the ignition is cut completely. This rev
limiter alone will prevent over revving, but in the case of high powered drag engines coupled to an
automatic transmission or supercharged applications, this can be quite violent. This is best used alone in
naturally aspirated and turbo charged engines with a manual transmission.
L.3. FUEL CONTROL
L.3.a. No Fuel Cut
This setting will never cut fuel. This option will typically only be used with the 3-stage rev limit.
L.3.b. Fuel Cut
This setting will cut fuel completely on rev limit. This setting will typically only be used with the zero
degree advance timing option.
L.3.c. Progressive Fuel Cut
This option is the most powerful of all rev limit settings. Upon over revving, one injector event in 16 will
be skipped. If the revs continue to rise, after the RPM delay and the time specified by the Update Rate,
another injector event in 16 is skipped. This process will continue until all cylinders are cut or the revs
drop below the RPM delay value. When the RPMs are above the rev limit and below the delay RPM, the
number of cylinder events skipped will stay the same. If the revs drop below the rev limit and remain
above the hysteresis value, the number of injector events will be increased. This will help to maintain a
smooth consistent RPM when holding against the rev limiter.
M. Troubleshooting
Troubleshooting an engine management system is actually a fairly straightforward process. When
viewed in simple terms, an engine that is in good mechanical condition, but will not run properly, can only
need one of these three things:
M.1. Air, Fuel, and Spark
As a result, troubleshooting an engine problem can be divided into these three parameters. With laptop
software that allows the tuning of the engine as well as the diagnosis of potential engine sensor problems,
troubleshooting an electronically controlled engine is fairly simple.
M.2. Starting Problems
M.2.a. Air-Related Starting Problems
•
A small amount of air must enter the engine cranking in order for the engine to start.
o
Open the throttle a small amount during cranking. If the engine starts, manipulate the IAC
motor settings as outlined in
Section B.8.
for proper start-up parameters.
o
If the engine does not start with a small amount of throttle opening, look to either fuel or
spark-related problems.
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TECgt Manual Version 2.0
- Page 111 -
©2008 Electromotive, Inc.
