Ilde rough 2001 ford taurus low miles idles rough in park up to about 2000 rpm's and then seems to get better. In drive or reverse I can only get up to about 1100 rpm's at full throttle. I have already changed the mass air sensor, plugs, wires, distributer, o2 sensors, pcv. Need help

I think you are on the right track with a tune up. Replace the wires, air filter and oil as well. I also would run a cleaner through the fuel lines. An STP or a Lucas would be better.

IAC valve failure.

Could be IAC sensor maybe TPS sensor[RPM].

You will need to figure out if you have spark to the plugs, and if not- if you have voltage to the coil to proceed.

Hi, Seems like a possible inlet air leak or to low engine revs, tickover rpm to low.outside chance engine oil to thick, try lower vicousity engine oil. this sometimes works with a rebuilt motor. Could be engine is just still tight from rebuild,1-2000 miles running in should cure this. if still low mileage.

You have a massive vacuum leak somewhere. I would check the intake manifold gaskets for leaks and to see if the Idle Air Control valve is stuck open.

you have a bad temp sender,if this does not solve the rough idle than you have multiple issues and your idle control valve is not functioning properly try removing and cleaning it.its also referred to as IAC (intake air control)

it could be that the tick over is two slow in brive,,,
set it up to tickover at 850,,950 rpm (in drive)
or it could be a gear box fult like the drive plate has a crack in it,,,letting the torque converter slap about,,,
chech tick over first,,, bont adjust tick over in gear unless the brakes are held hard on,,,

Sounds like a sensor, probably not harmful to drive the car. If you hook up a diagnostic scanner it will give you a code, and if it's a better scanner, it'll tell you a general idea where the problem is coming from. From research that I've done, it sounds like a pulse generator.

If you don't have a scanner, maybe a friend does? or a diagnostic shop which costs some money.

your probably feeling a rough idle of the engine. need a tune up?

in park the engine is not loaded down, just idling at a low rpm=rough
in drive with brake on you have put some load on motor also at low rpm=rough
in drive on the road engine is at higher rpm, = smoother

generally 4 cylinder motors idle a bit rough, especially if one spark plug is not firing right or fouled or one bad spark plug wire. tune up may fix it. if it is not stumbling real bad or stalling then you can live with it.