I did this on a 91 Stanza with 2.4 engine. Discovered that the mechanic I paid to do the job broke the TC cover and tried to "fix" it with gasket sealer (told me the oil leak was due to a worn harmonic balancer shaft). I'm guessing he broke it by prying on the cover after he thought all the bolts were out. He was wrong, and I bet that you are too. When I went back in to find out why the timing chain was rattling a year later, I discovered the broken cover and that there were at least 2 more bolts than I thought. If I remember correctly, the bolts go from the engine into the cover, backwards from what you expect, and are on the lower half of the cover. Good luck.
The 1990 Stanza has a chain.
the markings on sprocket
I believe that it is a chain, I believe that it is a chain,
timing is 15 degrees before on both std and auto.
The 1989 Nissan Stanza 2.0 4 cylinder has a timing belt. This is also an Interferance Engine, and as such if the belt breaks, serious engine damage will occur. The belt should be replaced at 60,000 miles.
ca20? remove all the belts, water pump pulley, underdrive pulley, timing chain cover and timing belt and the water pump is accessible. I would replace the timing belt too.
at top dead center, camshaft mark at 12 o'clock and crank at 5 o'clock. belt should also have marks if it a Nissan belt.
The two bolts you are referrring to are accessed through the oil pan. You will need to remove the oil pan and possibly inner baffling to remove.
remove timing chain
One, remove the timing cover. The chain is under there. Don't forget timing of the chain.
Nissan ga15 timing diagram
The 1990 Stanza could have damage, depending on which engine is in the vehicle. Check to see which engine you have, and if it is listed as an interference engine. If it is the interference type, then the valves are probably bent and destroyed.