1991 Century Buick V6 starter replacement.

inside fuel tank

if you have the proper tools you will need to support the engine with a jack, undo the mount nuts and bolts remove them then remove the mount. you can use the jack to move the motor up or down depending on what needs to be done.

the fuel pumps circuit starts from the engines oil pressure sensor so replace that item next

First check your fuse box for a bad fuse, if no fuses bad then go to auto parts store and buy new element. They can show you which one you need

The crankshaft sensor is bad,or the ignition module,one of the two.

have you called a local dealer?

just look it up on google,

Should be the same but look at the pan on the trans should be the same. If the pans are the same and there are the same number of bolts in each pan then you should be fine.

if theres a cross bar the engine will need to be removed.
if not just remove all the bolts around the oilpan and remove it.