Originally Posted by
stevieturbo
Common rail is pretty much like a modern fuel injected car. A single fuel rail that supplies injectors at high pressure via the pump and electronically controlled injectors.
Older setups had a pump which controlled amount of fuel flow, then just blasted it to each injector as and when was appropriate. The old systems were totally mechanical, more recent stuff did have some degree of electronic control over the pump, but not the injectors.
Yeah Cummins used the older set up for years. The injector is actuated by a cam and variable fuel pressure governed RPM (MUI) they then moved over to (EUI) with there Quantum System although the MCR still varies pressure on the larger 60ltr plus units.
Theres loads of common rail systems. Mechanical Unit injection (MUI) Hydraulic Electronic Unit Injection (HEUI's <-- Fucking shite nitmare) Electronic Unit Injection (EUI) is the most used.
The latest EUI has upto 6 strategy's which includes Pre and Post cycle injection cycles to clean combustion.
Some like the HEUI have ORS systems that inject a small ammount of engine oil into the fuel and a tank replenishes as required. It's all about extended oil changes = Money
Don't get me started about Dual Electronic Unit Injectors (DEUI) twin function Variable timing
I will get my coat.