2000 Mercury Sable

2000 Mercury Sable 6 cyl Front Wheel Drive Automatic 125000 miles

Every once in awhile my car while not going very fast my car will stall, (not sure if that's the right word) but I can't accerlate. What I've done is switched between neutral and drive and sometimes that works, otherwise I have to put it in neutral and restart. It's only done this a few times in the past year and it happened twice the other day, but since then it's been fine. I changed the spark plugs awhile back because someone suggested that may help but obviously that was not the cause. The only other thing I thought of possibly is the fuel pressure regulator. Any ideas?
July 16, 2010.

Lack of acceleration, chugging, hesitating, bogging etc. Could be caused by one of the following below: Possibilities: Inspect and test all the following listed below: Oxygen sensor.
Catalytic converter.
Fuel injectors dirty/sticking.
Mass airflow sensor/Airflow meter.
Throttle position sensor.
Crankshaft position sensor
Knock sensor
Manifold absolute pressure sensor.
EGR Valve
Fuel pressure regulator leaking or defective fuel pump.
False air leakage.
Fuel contamination.
Foul/defective spark plugs.
Open spark plug wires.
Ignition coil/Coil packs defective.
Incorrect ignition timing.
Cap and rotor.

Note: If it doesn't apply disregard it.

Jul 18, 2010.