No
The only return pipe i can find is external to the head as the injectors are under the rocker cover, as far as im aware its gallery fed. each injector is independant and only takes what it needs. Its not common rail.
I tell you, when i came to open the bonnet and search for the injectors, it took me nearly an hour to realise they were under the rocker cover
The underpaid but overcharging tech fella at isuzu said this engine (not this one personaly) nearly sent isuzu bust, frought with problems