Haltech E6M - Manual (Page 10)

4
Tool/Supply Requirements
Installation of this system can be easily carried out by professional mechanics and most
experienced home mechanics if the following tools and components are available:
Voltmeter or Test Light
A selection of screwdrivers and spanners
Soldering Iron and solder (we recommend soldering all connections)
Wire Cutters and Pliers
Crimping Tool and assorted terminals
Drill with assorted drill bits
3/8" NPT Tap
14mm x 1.5 Tap
Electrical Tape or Heat Shrink tubing
Teflon pipe sealing tape
Nylon cable ties
Jeweller’s file (may be needed for mounting Throttle Position Sensor)
Mounting hardware for ECU and relays (mounts/bolts/screws)
IBM-PC compatible computer (preferably laptop) with at least 640kb, one disk drive and
an RS232 serial port.
A good quality Timing Light
How It Works
While the technology involved with electronic fuel injection is complex, the underlying
principles of its operation are really quite straightforward. The object of any fuel delivery
system in a gasoline engine is to determine the amount of air being drawn by the engine, and
supply the appropriate quantity of fuel to "burn" all the oxygen in that mass of air.
A carburettor uses primarily only one parameter to determine fuel metering: air speed. Higher
air speeds through the carburettor result in larger pressure drops across the venturis, and thus
more fuel is sucked through the jets.
Electronic fuel injection revolves around the use of solenoid-actuated injectors. These devices
employ a coil attached to a valve. When the coil is energised, the valve opens and fuel is
allowed to flow. As long as the pressure between the fuel and the air in front of the injector
nozzle is held constant, the rate of fuel flow will remain the same. By accurately controlling
the length of time the injector remains open, precise quantities of fuel can be metered to the
engine.
Since we have no convenient means of directly measuring the amount of air entering the
engine to determine the amount of fuel to deliver, we use a number of engine parameters to
determine an injection opening time. We build a table that breaks the engine's operation into a
series of rpm ranges. At each range, we consider the load on the engine, using either the
position of the throttle or the manifold pressure as a reference to the load on the engine.
Collectively, the ranges in this table (also called a look-up table), form a map of the
volumetric efficiency for the engine. Our standing assumption, therefore, is that for any