Tdi
OPERATION EDC
Injection pump
The injection pump incorporates actuator controlled
injected fuel quantity and solenoid operated timing
which operate in response to ECM signals against
driver demand, engine speed, temperature and boost
pressure.
Under start up conditions, signals from the crank
speed and water temperature sensors are relayed to
the ECM to control starting fuel quantity and injection
timing. Once the engine has started the ECM initiates
a ’closed loop’ monitoring system for fuel quantity,
injector timing and EGR relative to the appropriate
engine operating conditions.
A fuel cut-off facility and fuel temperature sensor is
incorporated in the pump.
As driver demand increases, signals from the throttle
position sensor are received by the ECM together with
crank speed and position pulses. The ECM signals
the injection pump to adjust fuel quantity and timing
relative to driver demand.
Injection timing sensor
An inductive sensor in No 4 injector body monitors
needle movement. This forms part of a ’closed loop’
system to control start of injection.
The system measures timing, relating the needle
movement signal to crank position (determined by
flywheel pulses from the engine speed sensor).
As engine coolant, fuel and air temperature changes
the ECM will correct fuel delivery and injection timing
for more efficient and accurate running. The ECM will
also make corrections for atmospheric pressure on
injection timing and EGR.
Air flow sensor
The Air Flow Sensor is mounted on a bracket
attached to the wheel arch valance, and connected by
hose to the air cleaner and turbo charger inlet.
Electronic Control Unit (ECM)
The EDC system is controlled by the ECM located in
the drivers footwell on the ’A’ post beneath the fascia.
The unit consists of a microprocessor with integrated
circuits and components and is connected to the main
harness by a 55 pin plug.
The unit consists of a flap valve airflow sensor which
measures the fresh air flow into the engine. The
sensor informs the ECM and, provided that the other
conditions are met, will implement EGR.
Inputs to the ECM from engine sensors control start of
injection, injected fuel quantity, fuel cut-off and EGR.
Engine speed sensor
The engine speed sensor is an active inductive sensor
mounted on the flywheel housing. Pulses from the
sensor activated by radial slots in the flywheel give
engine speed and position information to the ECM.
The ECM will also make corrections for engine
coolant, fuel and air temperature and atmospheric
pressure.
DESCRIPTION AND OPERATION
9
| Categories | Land Rover Discovery, Range Rover |
|---|---|
| Tags | Land Rover |
| Model Year | 1995 |
| Download File |
|
| Document Type | Workshop Manual |
| Language | English |
| Product Name | Discovery |
| Product Brand | Land Rover |
| Document File Type | |
| Publisher | landrover.com |
| Wikipedia's Page | http://en.wikipedia.org/wiki/Land_Rover |
| Copyright | Attribution Non-commercial |
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