PART A - Engine, Engine Management and Turbocharger

4. Maintenance, Service Adjustments and System Checks

4.1 Maintenance

The routine service schedule for the Sierra RS Cosworth is similar to the Sierra with the standard OHC-engine:

• First free Service at 1500 km
• Interim Service at 10.000 km and
• Standard Service at 20.000 km.

There are some exceptions which are included in the Sierra Service Voucher Booklet.
• The timing belt must be replaced at 80.000 km.

4.2 Service Adjustments

Throttle Plate Setting Screw

This screw is factory set and sealed and must not be altered in service.

Basic Idle Speed Control Screw

If the engine idle speed is not to specifi*cations at the first servicing (1500 km), it can be adjusted by means of the basic idle speed control screw
Disconnect multiplug from idle speed control valve, untighten locknut and adjust idle speed screw to achieve correct idle rpm with warm engine.
Idle speed: 850 rpm.

Note: After refitting the multiplug, the engine will raise to high engine rpm for a short period of time.

Throttle Position Sensor (TPS)-Adjust

After disassembling and re-assembling the switch can be adjusted within the limits of its elongated fastening holes.
Loosen fastening screws so that the housing snaps back by spring pressure to the original factory set throttle
plate adjustment.

1 = Idle speed control valve (ISC)
2 = Throttle plate setting screw
3 = Lock nut
4 = Basic idle speed control screw

Adjustment of Idle Mixture

Specified mixture CO at idle: 1-1.5% CO

The CO adjuster screw is located on the left hand side of the module multi plug.

Using a suitable tool carefully remove the tamper-proof plug thereby making sure that the tool does not penetrate the plug by more than 3 mm.

Excessive penetration may cause damage to the potentiometer located behind the adjuster screw:

To adjust CO the adjuster screw can be turned from stop to stop.

After correct adjustment the screw should be protected with a tamper proof plug.

Ignition Timing

The ignition timing (16 BTDC) cannot be adjusted in Service. The ignition timing is controlled by the ECU module and depends on engine temperature, load and manifold absolut pressure.

When replacing the distributor; the distri*butor must be inserted with the rotor aligning correctly with the TDC marking for cylinder NO.1 on the housing. A devi*ation of up to 4° will be compensated by the ECU module.

Retarding the Ignition Timing

To meet fuels with lower octane rating the ignition timing can be retarded electronically by 2. 4 or 6° by connecting the cable connectors (near the RH side of the ECU module) in various ways.

1 = Mixture control screw
2 = Cable for octane adjust

A = Distributor
B = RPM / TDC-Sensor
1 = Phase-sensor
2 = TDC marking - cyl. No.1
3 = Fastening bolt
4 = Fastening bolt
5 = 0.4 - 1.0 mm

Connections

Green plug to white plug = ignition retarded by 2°
Blue plug to white plug = ignition retarded by 4°
Green and blue plug to white plu = ignition retarded by 6°
(The white plug connects to chassis earth).

Adjusting the RPM / TDC Sensor

The air gap between the sensor and the eam should be 0.4 to 1.0 mm.
To adjust the air gap, the fastening bolt for the sensor must be untightened to enable resetting of the sensor.

Quick Test

The ECU module includes an internal selftest facility .
A warning light on the instrument panel will switch on if there is a defect in one of the sensor circuits.

Simultaneously a coded signal is fed to the test connector near the RH side of the ECU module
.
Connecting an LED tester to this test plug allows a quick test to be carried out on the following sensor circuits:
- RPM / TDC sensor
- Sensor - cylinder phase (distributor)
- Sensor - inlet air temperature (ACT)
- Sensor - engine coolant temperature (ECT)
- Sensor - inlet manifold absolute pressure (MAP)

The LED tester for the EEC IV-system (Loewener tool No. 0132060 or
Churchil tool No. 0472060) may be used.

The quick test is carried out with the engine not running but with the ignition switched on.

During the quick test the ECU module transmits codes in the form of electrical pulses.

Warning Light - Engine Management failure

Quick Test
1 = Test connector
2 = LED Tester
3 = Cable - battery plus