This part of site is an attempt to organize and add to the web resources for the Rover SD1
to form a cohesive and easily usable guide for those of us without easy access to
expert repair and/or advice. It is not offered in any way as a definitive source
and we take no responsibility for any errors that may exist.
the webmaster Rene Winters.
Servicing and Troubleshooting Procedures|
The system has been designed to run with a minimum of maintenance.
At the prescribed intervals air and fuel filters must be changed. They could affect
delivery rates and alter the mixture.
Depressurising The Fuel Circuit
Before disconnecting any fuel lines, thoroughly clean the unions, and for your own
safety depressurise the system!
This can be done by cranking the engine for a few seconds with the fuel pump isolated at
the inertia switch.
The throttle linkages, should be checked, cleaned and lubricated all fuel lines and
flexible air and vacuum hoses checked for leaks or signs of damage.
Of particular importance is the hose connecting the airflow meter to the throttle body.
A leak here would allow air to bypass the metering flap and would affect the overall
performance of the engine.
Check all electrical connections, especially that coolant temperature sensor.
If the engine is 'out of tune'' check all other items that could be at fault, for example
the ignition timing and plug gaps.
Idle Speed and Mixture Adjustment|
Now the procedure for checking idle speed and mixture settings. First connect the
tachometer and the CO meter.
The CO meter probe is connected to the exhaust system, at one of the tapping points
ahead of each catalyst. On UK specification cars, the probe can be positioned in the
exhaust tail pipe.
Start the engine and allow it to warm up FULLY!
Idle speed can now be checked. If adjustment is necessary, it can be made by this screw
on the throttle body. Turning the screw clockwise reduces idle speed.
The screw alters the cross-section of a throttle plate bypass channel.
Mixture adjustment is made by this screw on the airflow meter, turning it clockwise
enriches the mixture. The screw is covered by a plastic plug. It must be replaced with
another, of the appropriate colour, after any adjustment has been made.
The screw alters the cross-section of a channel bypassing the metering flap.
After adjusting the mixture the idle speed should be rechecked and adjusted if necessary.
The screw should then be secured by the locknut.
As you can imagine, troubleshooting the electrical circuit could be quite an involved
procedure, but don't despair, this Epitest unit developed by LUCAS will simplify the task.
It is supplied with a troubleshooting procedure.
The Epitest Unit |
The Epitest unit is connected to the ECU multiway harness connector, using these two
connectors, and is used in conjunction with a pressure gauge, also supplied with the
The gauge is connected between the fuel rail and the cold-start injector. It enables
accurate pressure checks to be carried out. Before connecting the gauge, for your own
safety, depressurise the fuel system and allow the engine to cool down. A rag should be
available to mop up any spilt fuel.
Finally a few words of warning. The ECU is a sensitive electronic device and can easily
he damaged as a result of bad practice.
So only use a 12 volt battery and if it needs charging, or if you have to carry out
electrical welding on the car; disconnect it first, but not with the engine running.
Lastly be very careful when using underbonnet cleaning equipment. You should avoid any
equipment that could force cleaning agent into the components and their connections.
This could lead to corrosion or short circuits.
You should now be sufficiently knowledgeable to understand how the system works but this
4 parts are its title suggests is only an introduction to fuel injection.