Also, how is yr rear crankshaft seal? The Jaguar PCV system maintains a slight vacuum in the crankcase, prevents oil vapor being pumped out of the rear crankcase (rope) seal. Without manifold vacuum this is compromised?
Efi batch fueling is how Jaguar (& everybody, incl. yr XJS) did it before microprocessors got powerful/fast enough for “sequential” fueling. Sequential fueling is when each injector is fired in sequence, each injection is timed/related to the intake valve opening. For sequential fueling the ECU needs to have a dedicated injector output for each cylinder, i.e. for V12 the ECU needs to have 12 injector outputs. You also need a camshaft position sensor, batch fueling requires a crank position sensor.
Per other explanations, the benefit of sequential fueling over batch fueling is increased part-load efficiency. Sequential fueling does not enable more power. To realise the efficiency benefits of sequential fueling requires A LOT of dyno-tuning (rolling road), incl. to optimize the timing/relationship between injection and intake across the entire operating range. Otherwise, even though the car may perform perfectly ok, it may not be as good as it could, maybe no better than a blind-tuned batch fueling setup. I.e. its all in the tune. Optimising sequential fueling used to be time consuming and expensive. Less so today by using latest generation ECU’s that have adaptive/learning mode/function, able to autotune themselves on a rolling road to a limited degree.
One advantage of high end aftermarket ECU’s is that they are backwards compatible. Having capability for sequential, flex fueling and sequential (coil per plug) ignition does not prevent you starting with the simplest configuration, upgrading as yr understanding and needs develop. Adaptronic modular design is specifically to support this. I.e for 12 cyl fully sequential fueling and ignition (no other user configurable ECU does this?) I purchase an additional module, plugs in internally. Each module has it's own cpu so u can max out the configuration without degrading performance.
Another advantage is opportunity for different software settings according to purpose. For example, imo sequential fueling is best for road cars and batch fueling the most practical for race cars. So, for your car I would have two configuration files. One would be for the cleanest, most efficient everyday use. Then on race day I would unbolt the cats, load the race file and head off to the track dribbling a trail of E85…
Adaptronic have 2 CAN channels, each 1 Mbps, on board terminating resistors can be switched on/off via the fully user-configurable software.