When you remove the distributor housing by removing the three bolts and pulling the housing towards the firewall to open it up, you cause the rotor to turn. If you pull it too far, the gears unmesh, In pushing it back together, the gears may not mesh exactly in the same position as when they came apart.
At this point, you need to hand crank the engine until the 10 degree BTDC mark on the flywheel is aligned with the notch on the inspection hole in the bellhousing (driver' side - there may be a rubber plug in the inspection hole) then remove the valve cover and check the postion of the valves on the #1 cylinder.

They should be closed (cam lobes away from the rocker arms) indicating that the #1 cylinder is in the ignition cycle. If not, then you need to turn the crank clockwise until the timing mark reappears and/or the #1 valves are in the closed position.

Remove the distributor cap and check to see if the rotor point is aimed at the #1 sparkplug.

If not, either adjust accoringly or remove the adjuster bolt, extract the rotor shaft then re-insert it so that when reseated it points at the #1 sparkplug point AND the ajusted bolt is in the middle of the adjuster range.

It may take several tries to do this as when you remove and re-insert the rotor shaft as it will rotate when it meshes with the driving gear on the camshaft.
Once this is done, your engine will run correctly.
Pics courtesy of Chilton's Total Car Care Import Trucks and SUVs 2-CD set -- run out in a BUYING FRENZY and get a copy! Part # C3050
Hope this helps!