86 uses a Hall Sensor in the Distributor. 89 on uses a RPM Sensor on the bell housing for ignition timing. At a minimum you need to use your old distributor with your 86 ignition system. Since the 86 & 89 model years used different Bosch Systems, LH 2.1 & 2.4 respectively you may have other issues to deal with to make it run smooth.

Ideally I would convert the whole setup to the newer LH2.4.

Maybe someone else who has do this can be more help.

Good Luck!

Danny Mac