A 1992 Mercury Grand Marquis came from the factory with ( 5W-30 )
The fuse box diagram for the 1992-1994 Mercury Grand Marquis can be found here: http://www.autozone.com/az/cds/en_us/0900823d/80/19/31/35/0900823d80193135/repairInfoPages.htm Just scroll down and click on Figure 4.
Yes , the 4.6 liter , SOHC , V8 engine in a 1992 Mercury Grand Marquis is fuel injected
It is called a window Regulator go on line and you will find a picture of it. I have replaced 3 on mine.
windshield from 1992-1997 will fit all
The most common is 13726548.
Take it to Best Buy
Anything's possible (...but why?)
8 spark plugs
In the front of the engine behind the A/C condensor
The fuel pump is inside the fuel tank.
Presumably however much the gauge reads...