CIS injection question

[Joshua Van Tol]

>On every CIS injected car that I have seen, there has always been a fuel
>hose from the fuel distributer to each injector. So..an I5 engine has 5
>hoses etc. My question is - why? Since all the injectors are merrily
>squirting fuel all the time when the engine is running, wouldn't it save
>money to have a single fuel hose into a fuel rail connecting all the
>injectors, just like the typical pulsed injection system?
>The Bosch guys are a smart bunch, so I'm sure there's a good reason. Can
>anyone tell me what it is?
>
>Vic Norman  1991 100

The flow isn't strictly regulated by pressure. Each injector is a bit 
different, and takes a bit more or less pressure to flow a certain 
amount. Therefore, the way fuel is metered is that it's run through a 
calibrated orifice in the metering head (the size of which is 
controlled by the airflow plate position) and the pressure drop 
across this is maintained at a specific value. Thus the flow rate to 
all the injectors is the same, regardless of minor variations in 
injectors.
-- 
Joshua Van Tol -- josh at spiny.com