HI,

All sounds suspect, if you remove the vacuum hose from the ignition ECU,
the car will not function 100%, as from this and other sensors works out the ignition advance and retard, ie distributor for speed reference, engine load,
(vacuum) and temperature signals, dertermines the correct spark ignition (advance) also controls boost limit from amal valve with input from air charge temp
sensor, checks for too high boost etc, and also retards the ignition if air temp to high,, just get it chipped and setup correctly, before you have major problems
R5, totally different as on carb,

DAVE R