Friday, Feb 26, 2016 at 18:58
The older, lower pressure injectors will last a lot longer, than the current, very high pressure, common rail injectors.
The reasons are simple. The older engines injected once per power stroke - the current piezo-electric injectors inject multiple times on a power stroke to improve fuel combustion and economy, and to reduce diesel injection "clatter".
The current piezo-electric injectors have multiple orifices, whereas a lot of the older injectors have only one orifice.
Multiple orifices means finer orifices, and therefore a higher chance of blockages via wear material from within the fuel system, and via carbon from combustion.
Current injectors operate at much higher pressures, therefore operating clearances are even finer than the old-style injectors (which often had 1/10,000 inch clearance between moving parts).
I was in an Isuzu dealership recently and they had a huge advert on the counter, with accompanying comprehensive literature, showing how important it is to ensure that the newest injectors are comprehensively cleaned by the dealership, using factory equipment, every 100,000kms, to ensure best injector performance.
In essence, the three factors that guide you towards injector servicing are hard starting, excessive black exhaust smoke, and worsening fuel consumption.
However, in the case of the exhaust smoke
check, you need to have someone following you to determine just how bad your black smoke problem is.
Some black smoke under hard acceleration is allowable, but black smoke on a steady throttle is not - and neither is black smoke when pulling a steady load with a steady throttle, allowable.
Emitting visible black smoke for 10 secs or longer is enough reason to have your vehicle defected, according to most State traffic regulations.
I would not be replacing injectors at 100,000kms unless the engine definitely showed signs of hard starting, increased fuel consumption, or increasing levels of black smoke.
Valve clearance adjustment is a simple maintenance job that SHOULD be done every 100,000kms.
You will often be surprised at what a difference a valve clearance adjustment will make, to performance.
Cheers, Ron.
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