CRD Diesel's

demon seed said

Maybe an even simpler explanation is each fuel injector is operated by a rocker arm much like the intake and exhaust valve rocker arms and when the rocker pushes on the "plunger" part of the injector very high pressure diesel is injected into the combustion chamber. The rocker is operated either by a push rod and cam or just from an overhead cam.

Terry

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The only diesels I'm familiar with that use a rocker arm or cam lobe are some of the TDI VW's. My wife's 04.5 is that way. Older 12 valve Cummins 5.9's and virtually all the older large truck diesels used only timed fuel pressure to pop the injector.

The new common rail diesels don't use any mechanical actuators of any kind and earlier IH (Navistar also used in the Fords), and Cat diesels used a seperate high pressure oil pump (using engine oil) in a common channel cast into the head to help open the injectors along with electronic controls.

I believe the 60 series Detroit diesels also use this method but I'm not certain of that.

I am of course not an expert on all the diesels out there, I'm familiar with a few only with most of my experience pertaining to the Cummins 5.9 as installed in the Dodge truck.