How to change the fuel filter on 1990 Buick Century V4

SOURCE: Where is the fuel filter located for Buick Century 2001

The fuel filter is located underneath the car in front of the gas tank.
You have release the fuel pressure. Remove the fuel filler cap, locate the fuel test port on the fuel rail on the passenger side on the end of the right real fuel rail for a 3.1L engine.
3.8L engine yhr test port is located at the pressure regulator under the trim cover.

SOURCE: how do I change the fuel filter in a 1999 Buick Century Custom?

Philly, the fuel filter is attached to the frame in front of the gas tank, under the driver side of the car. You must relieve the pressure in the fuel line before you start, and it is also recommended that you disconnect the neg. battery cable. After disconnecting the neg. cable, remove the gas cap. Next, look under the hood on the fuel rail for a shrader valve (like the type on a bicycle tire). Place a rag under the valve, remove the cap, and press the valve in with a plastic pen to relieve the pressure in the line. You can now go under the car to remove the filter. You can disconnect the fuel lines easily with an inexpensive plastic disk made for this purpose (only a few $ for several sizes at a parts store). Be careful of fuel in the line that will drain out, no smoking or sparks during this procedure. Should be 1 bolt securing filter to frame. Note arrow on new filter, and install in the correct direction. Replace cap on shrader valve, put gas cap back on, reconnect battery cable. The low coolant light is probably a faulty sensor signaling that it's low, when it's actually ok. Look for wires coming from the reservoir bottle, you should be able to find the sensor at the end of the wires to replace it. If you change the fuel filter in a garage, leave the door open for air circulation, gas fumes can explode easily, having the door open will help dissipate the fumes.

SOURCE: Change Engine Air Filter in 1999 Buick Century

Well you didn't say what engine is in it so,I'll wing it. Assuming it's a v6, the airbox is located in the front,probably driver side. Remove the 4 or 5 wing nuts or Phillips head screws. Gently but firmly lift the top housing & slide the old filter out. Put the new one in,making sure it's in the same way as the old one came out. It can't go in upside down anyway but I'm being specific. Re-install the housing & done!!

SOURCE: my dash light went out on my 1990 buick century.

Find your fuse box, read the cover and find the cigarette lighter and match the drawings with the arrangement of the fuses, when you find it, pull it out and check if blown out or open circuit, then replace it with a the same value of amp. ok

SOURCE: 1990 buick century

It sounds like the engine computer. Also check the resistance in the injectors and o-rings. O2 sensor and coolant temp sensor could give you a problem.