99% of the time, it's as Eddy and Curtis have said - incorrect distributor timing.

Again -

1) remove all spark plugs
2) put your fingertip over the #1 plug hole (that's the front hole on the passenger side)
3) rotate the engine until you feel air pressure against your fingertip
4) continue rotation until the TDC mark on the harmonic balancer is aligned with the timing mark on the front cover
5) insert the distributor so that the rotor is pointing almost straight to the rear
6) remove the cover from the dead-end connector located on the firewall just under the wiper motor (that's where it's located on the '89 - not sure about the '92)and ground the pin to the engine block with a jumber
7) start the engine, let it warm to operating temperature and set the ignition lead to 5? BTDC
8) lock down the distributor and remove the jumper
9) the ignition lead should now read 15-17? BTDC as read on the front cover marks

The problem with understanding this at first glance is because the distributor cap re-routes the tower sequence firing order and this has fooled many good mechanics. Turn the distributor over and look inside to see the tunnel that re-routes #1 to the rear of the distributor. You'll realize that #1 tower is not where you think it should be.

Frank