What do I get?
You will get updated software to install into a Lucas 14CUX “Hotwire” Fuel Injection
computer. The software is supplied in an EPROM chip with the necessary decoder board, all
packed in an anti-static shipping box. Fitting instructions are supplied, with full colour
This software is intended for 4.2 Litre engines, where the car is still using the standard Lucas
5AM airflow meter and standard Land Rover ERR722 fuel injectors. For best results the fuel
pressure should remain set to the standard 2.5 Bar (36 PSI), since the fuel injectors are
operating comfortably within their maximum flow capacity.
What are the benefits?
For every car manufacturer (even sports cars), exhaust emissions are the first priority that
must be met when mapping the standard engine. This inevitably involves various
compromises to be made over the ideal settings for economy or power. Manufacturer’s
emission tests are very much more stringent than the MOT test, and include the warm-up
cycle which is where most of the problem emissions occur.
Emissions compliance requires a very flat air/fuel mixture, which is neither ideal for economy
nor power. The compromises in the fuelling also require very conservative ignition timing.
Once the fuelling issues are addressed then more adventurous ignition timing may be used.
Such characteristics are not unique to any fuel injection system or vehicle manufacturer. This
behaviour is displayed by most modern cars, which have to comply with very tough exhaust
emission legislation as the first priority. Emission standards for manufacturers are so
demanding that they need to use every trick in the book to ensure compliance.
It is possible to achieve 10-15 BHP power increases with 10-15% economy improvements
once these compromises are removed, and the engine will rev much more smoothly and
eagerly. Exhaust emissions are completely unaffected for the purpose of the MOT test.
Many other operating characteristics are addressed by this upgrade. These include idle speed,
idle stability, cold starting, cranking fuelling, rev limit, etc. Therefore this is a thorough
treatment of the entire set of operating characteristics that goes far beyond ignition or
The standard fuel map only goes up to 5500 RPM which is fine for a standard Land Rover
Discovery or Range Rover, but is not best suited to the more sporting variants. Where
appropriate the map is extended to 6000-6500 RPM as determined by the application.
As you would expect, the upgrades are fully compatible with the standard Land Rover vehicle
diagnostic and security systems. Service and fault diagnosis procedures are unaltered, and
the upgrade is undetectable to Land Rover TestBook, AutoLogic, RovaCom or Lucas/Sun PDL
There are two families of Lucas 14CUX ECUs. Before you place your order we need to check
which type you have, so please contact us first. All original TVR supplied ECUs have “plug-in”
chips, with the appropriate socket fitted. If the ECU is not original (e.g. replaced by a Land
Rover standard version to fix a fault) then it may not have a socket, so in this case it will be
necessary to have a socket fitted to receive the new chip. We can arrange this for you at a
small cost, but again it is essential that you contact us first.
The settings used in this software are based on examples taken from dyno testing more than
2,500 Rover V8 engines over sixteen years. Occasionally there are engines that fall outside
this range, so if there is any odd behaviour observed after installing the software then it is
important that you get in contact straight away. Special versions of the software can be
produced to take account of these variations.
Maximum benefits will only be seen where there are no underlying problems or faults with
the engine. It is always recommended that you have the vehicle checked by a specialist. We
can also tailor the software to an individual car and owner at our four wheel drive rolling road
facilities at Cheltenham, Shrewsbury or Gatwick. Note that there are separate charges for this
Fuel injector problems are very common with the standard Lucas parts, and we recommend
that they should be ultrasonically cleaned and tested at least. There are very good modern
Bosch design injectors available also, which improve torque, efficiency, economy and
emissions. These are a good choice if the Lucas items are defective, and specific versions of
Fuel supplied during engine cranking is very generous (to say the least), so this has been
decreased to reduce the risk of flooding. A small starting delay (approximately 2-3 engine
revolutions) has been introduced to allow oil pressure to build up before starting.
Engine temperature map fuel compensation map features decreased cold and warm up
fuelling to reduce the risk of flooding.
The engine’s fuel requirements are determined by engine speed and load. Engine load is
determined by measuring the true mass of air that the engine is consuming at any particular
speed, using the “hotwire” airflow meter. Mass airflow is proportional to the torque that the
engine is producing, and hence it is closely related to the engine capacity. This is also heavily
influenced by atmospheric conditions such as barometric pressure, temperature, etc.
Therefore it is vital that the software is programmed with the correct maximum mass air
consumption of the engine, known as airflow meter scaling. This is vital for good driveability
and fuel economy especially on large capacity engines, and allows correct control of part
throttle fuelling. Note that airflow meter scaling determines when the top of the fuel map is
reached. When using an engine of larger capacity than the software was designed for, the
top of the map will be reached too soon. This leads to over-fuelling at part throttle, and
under-fuelling at full throttle.
A re-profiled Fuel Map which provides good fuel economy on part throttle, and allows engine
to rev more freely (standard profile reduces fuelling heavily after 4000RPM). This produces
quicker, more progressive throttle response and better mid range torque.
Fuel map range is extended from the current 5500 RPM upper limit, to 6000-6500 RPM where
Idle speed is lifted to give smoother idle. For automatics this allows a smaller differential
between Neutral/In-gear idle speeds, thereby reducing transmission “clunk” when selecting
gear. The idle speed control system also determines the amount of engine braking, and this
has also been revised to provide a small but useful increase in this property.
The software limits road speed to standard 113 MPH, which is removed (although not
applicable to TVRs).
“Check Engine” (or MIL) lamp is enabled when any fault codes are present in the ECU,
although the wiring in earlier TVRs will still stop it working! This lamp is disabled in the
software for all territories except North American Specification (NAS) vehicles.
If you are overseas please make contact and we’ll advise of the postal charges applicable.
All chip sets are made to order and are non refundable.