LPG gas system

System solution for upgrading the Motronic M1.5.4 (739 402) or compatible 4-cylinder engine management systems with liquefied petroleum gas (LPG).

The system consists of the following components:

739 405-01 Control unit LPG

Original 4-cylinder gas controller with connectors on 4-mm safety sockets. Additionally, with control element and USB interface. At the rear side there are four 7-pin connectors for connecting the devices 739 405-02 and 739 405-03. The connection to the LH-Motronic ECU 739 402 for signals of the injectors 1 to 4, the lambda sensor and the speed sensor is carried out at the front by laboratory cables. Via the integrated USB port, the controller can be connected directly to a computer for the Self-diagnosis and the reprogramming.

739 405-02 Tank fitting

Tank fitting with shut-off valve, fuel level sensor and display. The fill port is connected to a compressed air coupling for plugging to an existing compressed air supply or directly to a compressor, for example 744 600. The tank fitting has a connection for the connecting hose to the evaporator. In addition a "Dish" filling fitting is mounted as a sample (without function). On the rear side there is one 7-pin socket for connection to the control unit 739 405-01.

739 405-03 System panel gas

Central unit with shut-off valve engine compartment, evaporator with coolant temperature sensor, MAP sensor and gas mass distributor rail with gas pressure and temperature sensor.
In the gas suction rail there is a gas filter.
The gas tubing of the injection valves can be fixed using the holder clips on the fuel injectors.
The gas tubes are closed with sound absorbers.

The shut-off valve is connected to the gas hose using a tank fitting. At the rear side there are three 7-pin sockets for the connection with the control unit 739 405-01.

739 405-04 Overlay mask

An overlay mask as a supplement for the motor substitute panel 739 191.

Using the bundled software, the system can be diagnosed and adjusted as well as optimized, too.