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XDI200 Manual Version 0.1
- Page 62 -
©2017 Electromotive, Inc.
6.2 Tachometer Output
The tachometer output on the
XDI200
is a +12 Volt square
wave. Each time a coil fires, a “tach pulse” is generated. Therefore,
the output from the tachometer signal is ground, then +12 Volts for 30
degrees of crankshaft rotation starting at each TDC/spark event. A 4-
cylinder will output 2 tach pulses per revolution, a 6-cylinder will
output 3 tach pulses per revolution, an 8-cylinder will output 4 tach
pulses per revolution. For applications that have a tachometer
configured for a different number of cylinders than the engine (i.e. a
6-cylinder car that was converted to an 8-cylinder), there is the option of changing the tach output
type in the software.
This type of signal is compatible with most new-style tachometers. However, some older
tachometers trigger off the high-voltage signal from the ignition coil (C-). These types of coils
require the use of a tachometer amplifier, since they are designed to trigger off of a 120 Volt
signal. Tachometer amplifiers (PN: 150-15210) are available from Electromotive to suit these
applications.
Figure 76:
Typical tachometer wiring.
6.3 Fuel Pump Relay Output
The fuel pump output is designed to provide activation of the fuel pump relay on a vehicle.
It is NOT designed to power the fuel pump directly. See
Figure 77
for wiring instructions.
The software allows the user to define the amount of time that the fuel pump primes the
system when the
XDI200
is first turned on. This ensures adequate fuel rail pressure on start-up.
When the
XDI200
is first turned on, the fuel pump will run for the amount of time defined in
the software. If the engine is not cranked during or after this time, the fuel pump will turn off.
Once the engine is cranked, the fuel pump will turn back on. Essentially, the fuel pump should
always be running when the engine is rotating.
CAUTION:
