Important things to be noted when using a wood gas equipped vehicle:
- The wood gas system must be designed to produce the best possible maximum power. For this reason the idling properties are not as good as those of a gasoline operated ICE. The idling speed is high. Often the ICE does not run properly with speeds below 1400 r/min. If the ICE is let to idle for a longer time (coffee break, lunch hour) the temperature in the combustion chamber drops and the generated gas contains tar. Therefore it is recommended to turn the ICE off when it is not used.
- Starting to drive
- Use a low gear when starting to drive. When more power is required quickly the engine usually stops because enough gas cannot be generated or the driver can not adjust the power control flaps quickly enough. The wood gas generator system works best when the load on the ICE is the same all the time.
- Filling fuel
- Do not inhale the gasses coming out from the fuel reservoir. Never use all fuel in the reservoir. If all fuel is used also the charcoal is gone and the temperature of the generator rises very much. In this case new charcoal must be added into the generator before adding new fuel. The best way is to refill fuel when there is much fuel left in the funnel. Doing this ensures that new fuel has time to dry enough and the generator can continuously generate gas with good quality.
Most common malfunctions during operation
Power goes slowly down even if the fuel is proper. Air consumption is lower than normally. Possible faults:
- Charcoal layer in the generator is clogged. Usually the faulty part is the hearth. The hearth moves too little or too slowly or it is too dense for the fuel used.
- Air leak on the generator. The lower part of the generator is extremely hot and fuel consumption is higher than normally.
- Air leak in the piping or in the filter. This fault is best noticed when gas (smoke) comes out from the system after the ICE is stopped.
- Filter is clogged due to ignored cleaning.
- An arch is formed in the combustion chamber. It must be removed with a steel bar. The most common reason for arch formation is wood chips with uneven or too big size.
The engine stops with no warning. Possible faults:
- Generator has run out of fuel and it is very hot, usually even the outer shell is glowing in red color.
- Collection tanks for condensed liquid are overfilled. The engine stops at once if especially the distribution reservoir is overfilled.
- The need of power rises (starting to drive or climbing a hill) quickly and the driver has not been prepared for this.
Tar formation. If there is tar in the gas this is usually noticed by:
- The engine starts knocking suddenly now and then. The inlet valves are stuck with tar and can not move freely.
- The valve push rods of the engine are permanently bent when the engine is started. The inlet valve is completely stuck with tar.
- Condensed liquid in the cooler and/or distribution reservoir is sticky - normally it is not.
- Starting the cold engine is difficult. Engine oil is sticky and dark and smells tar.
Translated by Olli.