01 mercury cougar2.5, last 3 to days car cuts off when come to complete stop.new plugs,plug wires,fuel filter,gas cap,fuses,both on inside & under hood.i need diagram for fuel systems front to

replace your fuel filter, and air filter ! you mean your fuel pump turns on , correct ? how do you know this for sure ? check all fuses, and especially GROUNDS ! ground wires get overlooked , and they should'nt . without them, you got nothing !!! tune-up lately ? replace spark plugs & wires ! distributor cap & rotor . oil change lately ? do it ! spark plug wires get old, hard, and crack, causing them to short out ! check all vacuum lines, if you have a throttlebody, tighten the mounting bolts, they do get loose !

this sounds like the carburetor is dirty internaly and needs a rebuild to correct the problem.if it was the fuel pump it would not matter if you held the pedal wide open or not it would not pump gas.you mention plug wires but not mention spark plugs specifically.these are the items that are normally replaced when a tune-up is done.plugs,cap rotor,points,condensor,plug wires if needed,air filter,fuel filter,set point gap,set ignition timing,adjust carb mixture.

do you have an engine light?1) check your spark plugs first. when is the last time you had a tune-up? it could be the ignition/timing. might need a new distributor cap/spark plugs/plug wiring. 2) check your intake and look for any vaccum leaks and check your engine light if you do, if you do and its a mass air flow input low, then you need a new maf sensor. 3) if you have a clean fuel system, then that is eliminated as a problem.

When was last tune up? Plugs, wires, all fluids & filters - especially fuel filter???? I'd start there and run a good fuel system cleaner through it and avoid cheap gas.

Start with a complete tune-up

Plug wires can cause this.

Do spark plugs, spark plug wires, distributor cap, rotor cap, spark plug wires, fuel filter, air filter, oil & oil filter.

People often neglect these simple things which could save your motor, maintain it's efficiency plus improve gas mileage.

Distributor rotor inside check that if it's a v6 then check ignition cool that connects to distributor more need replacement.

if you can't hear the fuel pump cut in for 2 or 3 seconds when you first turn the key to the "run" position, that will be the problem. The pump is inside the gas tank. You should be able to hear it hum for a couple of seconds. If not, make sure there is power to it. If it has power, but doesn't work... remove and replace.
If you can hear it, try the fuel filter. It may be completely plugged.
Check for spark if you haven't already.

OK, the gas cap and fuel filter things are fair W-A-Guesstimates...but you need to supply more info for any of us to help you accurately.

How were you driving when it "cut off"? Were you driving along smoothly at a fixed speed over 35mph or on the freeway at cruise? OR, were you accelerating from a stop, or pressing hard on the gas to accel hard or to go up a hill, were you turning...had the engine been running awhile(Was it fully warmed) or was this immediately after startup?

Fuel filters dont come and go. If its plugged causing loss of power, waiting 1/2 an hour or overnight wont unplug it and make it run better. The Catalytic converter could plug up and the symptoms are nearly IDENTICAL to a plugegd fuel filter in most cases. If the car cut off only under heavy load (acceleration or up a hill) then it still may be the fuel filter restricting flow. However if it cut off at idle or when coming to a stop, the odds say it isnt as they rarely plug instantly (Only if some kid dumped sugar or **** in your tank). They plug up slowly and regularly so you will 1st noticet he problem usually for days or weeks as only under acceleration, but it will usually idle FINE till it plugs completely. If it even IS a fuel problem. You REALLY REALLY need to get the trouble code that turned on the Check Engine lamp pulled for you with a scan tool. Any repair shop should be able to do that for a diagnsotic fee, or some auto parts stores still will do it for free or a fixed rental charge (like 10 dollars plus security). It may not even BE a fuel problem. It could be a crank sensor, sticking EGR, an electronic throttle problem, spark leakage...or 1000 other problems that can make it misfire, stall the engine, and cause general unhappiness and sore feet. We need to gather evidence and data to accurately direct you.

double chack your connectors specially afm sensor

before you drop tank again, check fuses & relay.then disconnect fuel line @ filter turn key to on position should hear fuel pump run and get gas stream out of line. if no flow from line new pump faulty be sure & remove negative battery cable first good luck.