[Stubby79]

The IDI VWs didn't have the best BSFC. A later (97-04, ALH/AHU) TDI has much better BSFC. I don't know how complex the earlier ECUs are, but the MK4 VW ECUs are quite a pain in the butt with their anti-theft stuff. Hopefully the 97-99s are more easily transplanted...

Cleaned or new injector nozzles will probably clear up your black smoke issue. The fuel probably isn't atomizing worth a damn as it is now, unless you simply have too large of nozzles on there.

BTW, a push trailer should be notably more efficient and simpler then a generator-trailer. Though I love the idea of generating power, it's a losing battle of efficiencies at every step. Putting the power directly to the ground will be the most efficient way, plus then your leaf's built in systems can regen safely without you modifying and messing up the battery pack or electrical system.