facelift occured in October 1989, so all JDM 1990 cars are facelift. You can spot the facelift by having the same tails as the US 91 xxxx/2000 models and the single lamp corner turn signals/headlamps with city lights, and instrument cluster which does away with the colour change switch.
If you're referring to the second facelift for 5MT vehicles (ie to Evolution spec), that happened in August 1990 - and you would definitely be able to tell by having the hood vents, 510cc injectors, 16G turbo, 3.909 diff ratios etc.
But all JDM 1990 models will be single board EEPROM.