The EFi (Electronic Fuel injection) system for the Rover SD1 is actually
the well known Bosch L-jetronic system adapted by Lucas. Most components are manufactured by
Boschje itself (As you can see by the "made in Germany" labels.......already a sign for the
German BMW connection?).
Fuel injection first appeared in Diesel engines back in 1927. Off course this was a Bosch
system. This German company can be seen as the main force behind all modern EFI systems.
The first 4-stroke production car equipped with fuel injection was the 1952 Mercedes Benz 300 SL
which had direct injection into the cylinders. Later on more advanced systems were developed
by Bosch. Shown below is a short overview.
|System||Principle||Built into||Mechanical injection
||Direct injection, Mechanical
||Mercedes 300 SL
|Electronic system, fuel quantity based on manifold pressure
||BMW 3.0Si (early types)|
Jaguar XJS/ XJ12
VW type 3/4
|Electronic system based on air flow, continuous fuel injection
Volvo 142, 144, 145
|Electronic system based on air flow, intermittent fuel injection
||Alfa Romeo GTV 2.5/Spider|
BMW 628/630 Csi
Lucas had its own Fuel injection system, based on Bosch, built into a Jaguar D-type back in 1957.
Later the Maseratis 3500GT, Sebring 109, 5000GT and 107 were also equipped with the Lucas
system. The real break through for Lucas came with the mechanical fuel injection system
built into the Thriumph 2.5PI range and the TR5/6.
The Triumph injection was
developed by Lucas after the first wave of U.S. anti-emissions regulations. However it soon
became clear the injection system would need extra environmental controls and that a carefully
set Zenith-Stromberg carburetor could also do the job. For extra power though the Lucas
injection proved to be very good. So this is how Europe got the Injection first and the U.S.
had to do with carburetors for that time! You can find the schematic for the mechanical
Lucas system below.
For the SD1's on the U.S. and Australian market an injection system based on Bosch L-jetronic
components was used. Thanks to the emission regulations power for the SD1 was down to 133 bhp
respectively 150 bhp for the Australian EFi, against 155 bhp for its European counterparts
equipped with two SU HIF 6 carburettors. The 22 bhp went into the catalytic converters
(not fitted on the Australian SD1's), the Oxygen sensor and a rather restrictive plenum chamber.
The U.S. cars could still reach 117 mph though, opposed to 126 mph for the Euro versions
When Rover became involved in motorsports in the early 80's the management and the Competition
department soon found eachother in creating a powerful SD1 for the upper market. The Australian
injection system was used as a basis with a better plenum chamber, a revised air-flow meter,
ECU, and a different distributor characteristic. Coupled with the additional compression
increase to 9.75:1 the power of the Vitesse as the car was called, went up to a healthy 190 bhp.
This EFi system was used in the same form in the Vandenplas EFi and in a somewhat detuned form
in the Range Rover line-up.
These pages will introduce you into the basics of the Bosch/Lucas L-jetronics system. Whether
for an SD1 or a Range Rover.
Lucas/Bosch L-Jetronic...the basics
Click on the map for a description of the selected part
Fuel is drawn from the tank to a high pressure pump which pushes the liquid gold through a
fine mazed filter to the fuel pressure regulator. The excess fuel is drained back into the tank.
The fuel is then transported through a fuel rail to the injectors and the cold start injector.
The air is drawn in from the air filter through the air flow sensor which incoporates a
temperature sensor. From there the air flows through the plenum chamber into the engine.
The injectors are opened for a short time.
The duration is calculated by the ECU and depends on:
- Air flow measured by the air flow sensor
- Air temperature
- Engine temperature
- Position of throttle butterfly