NIStune TYPE 1 V.3.5 - Manual (Page 30)

Nistune Type 1 Hardware Installation Page 30 of 33
1986-1988 HR31 RB20DET
Note the later year models (such as MEC-R70 do not require this modification)
1. Locate opamp daughter board
2. On reverse side of ECU count from the outside edge inwards and bridge pins 7 and 8 with
solder.
3. Connect a 5.1 volt zener diode with stripe side on pin 8 and other end on pin 6 (ground) as
pictured below
4. Rewire the AFM as per pinouts in the AFM section of the Nistune Software Users Manual