Just like what you see in a car wiring system, wiring harness is used in EFIgenset generator to connect all sensors, ECU, control panel, propane cylinder switch (see Cylinmatic section of this website) that makes service a breeze. Learned from the computer industry, plug-and-play is the way to go in our generator design. It only takes a few minutes to swap out the essential modular components to isolate the issues and to minimize down time, thus flattening the learning curve of the supporting team.


In fact, most gaseous fueled generators on the market use the carburetors as a throttle bodies because gaseous fuel is supplied under pressure and it does not need a Venturi tube to draw the fuel into the airstream. It can run on the household pipe vapor propane for its natural aspired engine. However, the volume of propane or natural gas supplied from the 1” diameter pipe may only deliver 14 – 18kW of power.
Here are the differences between Electronic Fuel Injection and Conventional Carbureted propane engines;
The fuel rail connected to the injectors that are mounted just above the intake manifoldclose to the intake valves of the cylinder head. It improves cylinder-to-cylinder fuel distribution of multi-port fuel injection; less fuel is needed for the same power output.
Conventional gaseous engine adapts single-point injection method where a single injector is mounted at the throttle body (the same location as was used by carburetor). The fuel passes through the intake manifold, enter the intake valve into the combustion chamber. It cannot provide an even fuel distribution between cylinders. When cylinder-to-cylinder distribution varies significantly, some cylinders receive excess fueland some receive insufficient fuel.
A perfect mixed fuel cannot burn completely in the combustion chamber if the ignition timing is too retarded or advanced. The exhaust gas from incomplete combustion contains excessive harmful carbon monoxide (CO) and nitrous oxide (NOx). The engine suffers excessive heat, vibration, power loss and shorter life span, let alone waste of energy. EFIgenset ECU integrates an ignition circuitry to give commands to the ignition module to fire the sparkplugs with accurate timing under all engine conditions to achieve maximum power output.
A mechanical ignition distributor shaft is geared by the engine with a vacuum tube from the intake manifold attached to the distributor to advance the ignition timing when engine requires more power. Their electronic ignition may simple means the distributor has pointless contact or pointless contact with an energy booster to amplify the sparks. The ignition timing works but not the most accurate for all engine conditions and resulted in higher toxic particles in the emission.
It involves massive engineering in ECU circuit design, software programming, tooling, and installation of electronic devices and sensors, wiring harness.
The justification for single-point injection was low cost. Many of the carburetor's supporting components - such as the air cleaner, intake manifold, and fuel line routing - could be reused.
When signaled by the ECU the fuel injector opens and sprays the pressurised fuel into the engine. The duration that the injector opens (called the pulse width) is proportional to the amount of fuel delivered. The throttle body’s butterfly valve is activated by a stepping motor energized by the ECU to allow the appropriate amount of air to enter into the intake manifold, and that proper Air/Fuel Ratio (AFR) is achieved.
When more power is needed, the speed governor commands the actuator to push open the throttle body’s butterfly valve by a push rod or cable to let the pre-mixed fuel into the intake manifold. The governor only provide one function, speed governing. It does not intervene the AFR for the best fuel mixture.
When a sudden maximum load is imposed on the generator, ECU receives the signal from the MAP sensor and calculates the appropriate amount of fuel (injector opening duration) to be injected into the combustion chamber. A sudden maximum load causes the wide opening of the throttle to maintain the preset rpm such as 3000 or 1500rpm. It is a challenge for most governors on the market to recover the speed within 1 or 2 seconds. Our ECU has a built-in advanced double feedback speed governor algorithm(see Magnum Governor section of this website) to coordinate the fuel injection duration and air inlet throttle stepping motor flawlessly. This governor technology keeps the rpm oscillation to the minimum, within 2 seconds, to avoid the voltage frequency fluctuation that may cause damages to the Inductance appliances. The lab report completed by Chongqing Quality Assurance & Research Institute reviews thetransient voltage recovery time of our JPLPG15N generator requires zero second, anunnoticeable fluctuation that leaves carbureted generator in the dust.
Conventional genset speed governor is not rpm oscillation friendly. A sudden maximum load imposed on the genset causes the governor’s push rod or cable to go back and forth to find the preset speed. Unlike EFI system that has Crank and Throttle Position sensors (TPS) to form a close-loop system, the conventional governor only have one speed sensor to feed speed signal to the processor to energize the push rod/cable solenoid. The governor does not have input signal as to how heavy the load is put on the generator. Trial and error is the fundamental method of solving problem – finding the right rpm. This process causes the rpm go and down for a longer duration than our Magnumgovernor.
It is a closed-loop system that provides continuous data to ECU for proper calibration of AFR with an exhaust gas oxygen sensor. An oxygen sensor which is installed in the exhaust system so that it can be used to determine how well the fuel has been combusted, therefore allowing closed loop operation. Exhaust emissions are cleaner because the more precise and accurate fuel metering reduces the concentration of toxic combustion byproducts leaving the engine.
It is an open-loop system that no mechanism is used to control the AFR. The inconsistent and unpredictable AFR results toxic combustion byproducts leaving the engine, especially during cold starting.
EFIgenset generator uses liquefied propane delivered through an engine-coolant heated pressures regulator (reducer) evaporator, come to the heated fuel rail next to the intake valves, and injected into the combustion chamber. It does not cause the freezing or condensation on the propane cylinder. It does not need two or more propane cylinders in parallel to supply stable propane. It consumes the last drop of propane in the cylinder that saves money in a long run.
The conventional carbureted vapor LPG generator can only utilize 80% of the fuel content from the propane cylinders because the rest of 20% does not have enough pressure to drive the generator. As well, the output power is discounted 3kW for the cylinder heat belts to avoid cylinder freezing. The efficiency is 7 – 10% less than an Electronic Fuel Injection generator. Therefore a rated 15wK conventional carburetedpropane generator wastes 3kW on heat belts plus 20%, about 8-10kg, of non-usable propane. It is estimated the real efficiency of a carbureted generator is 30% less than an EFI generator.
It offers smoother and more consistent transient throttle response, such as during quick throttle transitions, easier cold starting, more accurate adjustment to account for extremes of ambient temperatures and changes in air pressure, more stable idling, decreased maintenance needs, and better fuel efficiency. Summer or winter tuning is not necessary.
The engine is very sensitive to extremes of ambient temperatures and changes in air pressure, hard cold starting, constant adjustment of fuel pressure valve is needed when weather changes. It behaves like the old carbureted cars which need summer and winter tuning. These generators are not suitable for highland application unless you have a technician sleep next to it.
Essentially all LPG engines are gasoline engine conversions. They are not optimized for new fuel if engine tuning is not performed properly. EFI system is able to tune the engine for the best objectives to produce maximum power and fewer emissions.
There is no engine tuning of ignition timing, AFR for performance and less emission. They cannot take advantage of the low emission potential of LPG. Their engine fuel control system is not optimally calibrated for the new fuel, and resulted poorperformance, fuel economy, and emissions.
The major diferrence is:  We have brains, while others don't.