Formation and Removal of Injector Nozzle Deposits in Modern Diesel Cars 2013-01-1684
Deposits forming in the injector nozzle holes of modern diesel cars can reduce and disrupt the fuel injected into the combustion chamber, causing reduced or less efficient combustion, resulting in power loss and increased fuel consumption.
A study of the factors affecting injector nozzle tip temperature, a parameter critical to nozzle deposit formation, has been conducted in a Peugeot DW10 passenger car bench engine, as used in the industry standard CEC F-098 injector nozzle deposit test, .
The findings of the bench engine study were applied in the development of a Chassis Dynamometer (CD) based vehicle test method using Euro 5 compliant vehicles. The developed test method was refined to tune the conditions as far as practicable towards a realistic driving pattern whilst maintaining sufficient deposit forming tendency to enable test duration to be limited to a reasonable period.
The test method developed was applied to a fleet of Euro 4 and 5 compliant vehicles enabling the relative deposit sensitivity of the fleet to be assessed. Subsequently the deposit removal performance of conventional and novel diesel detergents was evaluated using the method developed.
Most of the fleet selected was susceptible to nozzle hole deposit formation and in all cases where deposit formation was detected, the novel diesel detergent outperformed the conventional detergent in recovering power and fuel efficiency losses due to deposit formation.
This work has provided insights into the susceptibility of modern diesel passenger vehicles to injector nozzle deposit formation and removal using a test method that is more realistic and widely applicable than industry standard methods.