Cant find where the spark plugs are in my mercury mariner 2005

Spark plug AGSF-32M Gap = 1.30-1.40 mm
(0.052-0.56 in)

Spark plug AGSF-32M Gap = 1.30-1.40 mm
(0.052-0.56 in)

There are many things it could be. in no particular order:
bad plugs
bad ignition wires
vacuum leak
bad valves
blown head
bad piston rings
bad injectors
there are more, but that's the short list. Any codes? check engine light?

did you use fuel addetive to stop fuel in carbs going off when you laid it up and winterize the cylinders etc ? check compressions , sparks and fuel is in all carbs as if you have sparks then carbs need stripping and cleaning ie, jets and float needles ! compressions to be no less than 100 psi on all 4 cyls !

Common ones

On mine it is under the car on the drivers side mounted under the back seat area in the inside of the frame rail.

look for the spark plug wire the plugs are bolted into the engine block you have to pull wire of spark plug first 5/8 deep socket should do the job good luck

The turn signal twists out from the back side of the headlight. Under the hood.

Clean or change the Spark Cables>
to cleab the pull them out and with antirust spray and clean

change alternator on a 2005 mercury mariner 2wd with a v6