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Understanding Low Pressure Testing of Aftermarket GDI Injectors

GDI (Gasoline Direct Injection) is new to some. Some love,some hate it but no matter what, Direct Injection for Gasoline engines is here to stay. There are many different manufacturers' names for GDI,but they all have the same feature; DIRECT INJECTION FOR A GASOLINE ENGINE.

The advantages it offers not only to the motorist but also the vehicle manufacturers, means there will never be a return to the original manifold/port injection systems.


GDI as we know it now has been in mass production since 1997, when Mitsubishi introduced the carisma, using Hitachi produced GDI injectors.

The initial launch was one of expectations and all the other VM's waited to see the acceptance of this type of engine. Even though most of them had already been working on such systems, they still wanted to see the motorists' reaction to the GDI vehicle.


The performance and economy was to be the winner and as the car was a family saloon, it appealed perfectly to the family man who wanted both. The die was cast and the exposure was good to start with. Any initial problems with the system were credited to teething problems caused by the fuel quality in the UK which was leaving deposits in the combustion chamber and this was having an adverse effect on the engine's all round performance, although that was not generally known at the time.

Injector Manufacturer Production Testing

The injector manufacturers like Bosch and Denso design and produce injectors to work at high pressure and during production they test the injectors at pressures over and beyond the operating pressure the system will operate at to ensure they are can perform correctly and are safe for extreme use while remaining within the tolerance they require.

In addition the injectors are checked for leaks, not only from the valve seat but also from the body and around the electrical connectors. Any leaks in these areas are not acceptable in any form but the chances of this happening are extremely remote but must be tested during production all the same.

All injectors initially produced by the manufacturers have already undertaken and passed a full range of endurance tests before they are accepted for production.


Vehicle Manufacturer Production Line & Warranty Injector Testing

Vehicle manufacturer's production line testing of products in the event of a problem is critical to the whole assembly line of a range of vehicles. Just one failure can halt the line until the reason for the failure has been identified and the problem resolved,whatever the cause.

For the VM's, should a component be found to be faulty, it could mean all the components in the batch supplied are withdrawn and replaced with a fresh batch. Should additional components found to be faulty, then the whole batch are returned to the manufacturer for replacement and in some cases a penalty is imposed on the component supplier.

Even worse is when a component is found to be faulty once the vehicles have been produced and sold in to the market and then begins to fail in daily use. The manufacturer has a number of options to correct it with the worst case scenario being to recall all the vehicles fitted with that batch of faulty components and replace them, with costs soaring and penalties increasing.

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