Most important factor which causes fuel injector clogging is drying of petrol on the injector nozzle. Unfortunately it can’t be avoided even if a car is primarily using CNG as fuel. Those cars which use petrol just for starting and immediately switch to CNG afterwards, have the same possibility of injector clogging as those which are driven on petrol. When an engine starts, the fuel flows through injectors and when it is turned off, the last drop dries on the minute hole of the fuel injector nozzle and leaves behind deposits. These deposits become stringent with the chamber heat and clog the injector. Efi cars essentially start on petrol even if their main fuel is CNG therefore the phenomenon of evaporation of petrol on the injector tip is common and equal in both type of cars. Gasoline additives and detergents already mixed into the gasoline we buy, help reduce this problem, but they can’t eliminate it entirely. Injectors periodically need to be cleaned. Some experts in the west recommend cleaning the injectors every 20,000 to 25,000 miles to keep them flowing at peak efficiency. But considering the fuel quality and climatic conditions of Pakistan I recommend injector cleaning after every 15 to 20 thousand kilometers.
Normally people hesitate in using fuel additives as they can cause harm to the fuel lining, some parts in the submersed fuel pump and could result in choked fuel filters. Some people don’t like use of such solvents as they end up carrying all the loosen sediments and dirt finally inside the engine. Of course additives are not the best solution for the problem but they can be helpful if few preventive measures are taken. Professional websites recommend change of fuel filters and engine oil after use of additive type fuel system and injector cleaners. Fuel additives are of no help in worse conditions where engine don’t start or there is too much of missing due to badly clogged injectors. No starting…no circulation of fuel…no cleaning.
Off vehicle sonic cleaning of injectors is internationally accepted most effective solution for injector clogging problem as it doesn’t risk any component of the fuel system. Results are acquired without having to drive hundreds of miles or burning tanks of fuel. Additives only make part cleaning of injectors whereas off vehicle sonic cleaning of injectors ensures complete cleaning in the injector nozzle. Observing the spray pattern and acquiring symmetric flow can only be achieved by means of off vehicle sonic cleaning.