Gas Injector – a Crucial Component
Gas injectors are among the most important components of 4th generation automotive LPG systems (sequential gas injection in the vapor phase). They must precisely measure the gas fuel doses, just like petrol injectors, so that the systems supervising the combustion process do not detect any irregularities or store related error codes, and the car maintains performance and parameters comparable to those on its base fuel.
Gas injectors can operate as single units, connected with special fittings and hoses, or supplied from dedicated distributors. They can also be mounted in a special rail, forming an injector rail made up of individual injectors. Multi-section rails (2-, 3-, and 4-section) are also very popular – these are single, inseparable units that cannot be divided into individual injectors.
Gas Injectors – Hard Workers
Injectors are some of the hardest-working components in the gas fuel system. If an injector opens once per engine cycle, i.e., every 2 crankshaft revolutions, then at an engine speed of 3,000 rpm each injector opens 1,500 times per minute of engine operation – that’s 90,000 times per hour.
Durability of Gas Injectors
The most durable gas injectors can operate without performance loss for up to 500,000,000 cycles, which corresponds to a mileage of over 220,000 km.
However, they are still mechanical components subject to normal wear as the vehicle mileage increases, despite numerous design solutions that reduce this process and improve durability.
Maintenance of the Gas System
One of the ways to minimize injector wear is proper maintenance of the automotive LPG system – that is, performing inspections on time and according to the manufacturer’s requirements. During these inspections, filters in the gas supply system are replaced. They prevent impurities that may appear in LPG from reaching the most precise components of the gas installation – namely, the gas injectors.
How to Recognize Worn Gas Injectors?
Symptoms of excessive wear or contamination of gas injectors may include
uneven engine operation, which can lead to error codes being recorded in the vehicle’s OBD system due to an incorrect air-fuel mixture. Uneven idling may manifest during driving as jerking, especially during rapid acceleration.
Poor operation of gas injectors may also be indicated by changes in fuel trim values within the vehicle’s OBD system.
Gas injectors, especially when maintenance has not been performed according to schedule, may become contaminated. In the autumn and winter months, when ambient temperatures are low, this can cause them to “stick,” resulting in uneven LPG operation and a tendency for the engine to stall shortly after the first morning switch to gas fuel. At low ambient temperatures, contaminants accumulated inside the injectors harden, limiting the mobility of their components and causing such behavior.
Selecting Gas Injectors
Damaged or contaminated gas injectors that cannot be cleaned of internal deposits should be replaced with new ones. Each gas injector has a specific capacity, expressed in HP per cylinder, which determines its suitability for engines of certain power levels.
However, the selection and replacement of gas injectors in an LPG system should be carried out by a specialized workshop. The process involves not only manual replacement but also recalibration of the system during a road test.