MembersPage/ZoltanAlmasi (2006-03-31 19:29:22)

Ford Sierra Cosworth 2wd

Originally with Weber-Marelli engine management.


Trigger

Engine RPM/TDC Sensor - VR type

The crankshaft pulley has 4 identical teeth spaced at precisely 90°. The sensor sends a signal to the module whenever a tooth passes a the sensor. From this signal the module determines engine speed (RPM) and the TDC position of each piston (crankshaft position).

crank_sensor.jpg

Note that pistons are 180 crankdegrees apart, so half of the pulses do NOT belong to pistons. This means this sensor requires camsync to operate. Not as convenient as a normal Bosch 60-2 or Rover K4-type pattern.

The distributor phase sensor (camsync) - also VR

The distributor is driven by the auxiliary shaft as on the standard ohc engine.

A phase sensor, located opposite a cam having two teeth separated at 90° (camdegrees) to each other, is fitted inside the distributor. At the passing of a tooth the sensor delivers a signal to the ECU. This signal is similar to the signal supplied by an RPM/TDC sensor fitted at the crankshaft pulley.

distr_phase_s.jpg

The signal from the distributor and the RPM/TDC sensor together enable module to identify the phase of each cylinder.

Note: the polarity of both sensors must be investigated. This is simple, but shouldn't be forgotten. And inverted if necessary, considering that the VR input HW senses the 0-crossing falling edge. (internally rising edge is configured when VR is used, since that is the output of the VR chip; but the VR input is always falling edge).

Unfortunately this trigger arrangement is not currently supported by firmware.


Other sensors - seems very smooth

The Throttle Position Sensor (TPS)

This unit is fitted to the throttle shaft and senses the throttle position. at idle speed voltage is 5.0-4.5 volts and at full throttle the voltage drops to 0.5 volt.

The Manifold Absolute Pressure (MAP) Sensor

Depending on the manifold pressure, the sensor regulates between 0.25 to 4.75 volts.

The Air Charge Temperature (ACT, MAT) Sensor

This sensor is of the NTC resistor type, its resistance decreases as temperatures increase.

Engine Coolant Temperature (ECT, CLT) Sensor

The ECT is also of NTC resistor type and its operating range is identical to that of the ACT.


Actuators:

Ignition module

The ECU sends a Spark-out signal to the ignition module

Coil - would you really want to use the unknown ignition module when this coil could be driven directly ?

The Fuel Injectors

The ECU provides accurate control of the solenoid operated fuel injectors to discharge fuel.

The Idle Speed Control (ISC) Valve

This unit is regulates the engine demand for air depending on the engine temperature, engine load, or swithed on accessories.

The valve, whichis controlled by a variable current from the ECU, adjust the air flow into the engine.

The valve is pwm modulated.

The Boost Pressure Control Valve

This solenoid valve is directly connected to the high pressure side of the turbocharger by a hose. Depending upon whether the valve is open or closed it will either "vent-off" a portion of the boost to the inlet side of the compressor (valve open) or direct it to the wastegate actuator (valve closed)

I need some advice about the hw configuration of vems.

Thx any help!