Starting Problem

I have a 2000 Mercury Villager Estate that began having starting issues some time ago.

This problem is not consistent. Sometimes you hop in and it fires off right away. Other times, you try to turn it over and all you get is the starter motor running. I do not run the starter for more than 8 - 10 seconds. Sometimes it takes 3 tries to get it started. Once it does fire off, it's as if it's mis-firing and slowly chugs until all pistons are firing happily in sequence. Once it's running, it runs like a champ.

Weather does not seem to affect this problem. Had the same symptoms in summer and winter. And, it does not matter if the engine is hot or cold...same symptoms.

I've replaced the plugs, plug wires, distributor, rotor, air filter, battery, and fuel filter all with high-dollar products.

Can anyone offer another suggestion before I take it in to take it in the rear?

Thanks!

if all you get is the starter motor running than the starter gear isnt making contact with the flywheel. the starter turns the flywheel which is bolted to the crank shaft the turns the engine. if its not making contact wheel maybe missing teeth. or the starter gear isnt pushing out to meet the wheel.
as far as running like crap, check your fuel pressure,
vacuum hoses, coil pack,and timing if possible.