just did one a 92, its not fun and the only easy way i found was using a 92-93 2.5TI engine harness and sbec. then custom cal. i did it with my n/a 92 es and made 16V turbo maserati head 2.2L and 523. do you have a wiring diagram for the 91 harness? i would be interested to see it because i might have to rewire a 91 tIII harness for this car to run my 92 stuff.