80,000 miles or 10 years.
it has a chain not a belt
I have a 91 240SX and had a similar issue, my Fuel Pump had to be replaced.
chain
15btdc
on the dampener pulley
if you mean when installing a timing chain, the keyway or square notch should be at 12 oclock and the mark should be at 3 oclock
it could be your timing is off
If you did not bench bleed the master, you need to do that.
20 degrees btdc with tps un plugged
It could be the timing chain guides. 240sx engines are notorious for this. The timing chain guides are made of cheap plastic and they wear out and break off after time. When the engine is started, the pieces get kicked up from the bottom of the oil pan and make a racket for a while. I don't think is causes much harm, though.
White smoke from the exhaust of your 1996 Nissan 240SX after replacing the timing chain may indicate that coolant is entering the combustion chamber, often due to a blown head gasket or a cracked cylinder head. It's also possible that oil is leaking into the cylinders if the timing chain replacement disturbed any seals or gaskets. To diagnose the issue, check for coolant in the oil and perform a compression test. If necessary, consult a mechanic for a thorough inspection.
Get a manual on your car, It will have pictures and everything,.