Need diagnosis - Stalling at low RPM while in Drive

[joshua_msu]

Hello, I was hoping I could get some info from you guys. I have a 99 Taurus with the 3.0 24V V6. It has around 70K on it. No major problems except a replaced speed sensor at about 52K, until yesterday.

When I started up the car in the morning, it began to rev on its own to about 2500 RPM. It came back down on its own after 20 secs. I put the car in reverse, and the engine began to stall out, the revs going to about 500 or so. I turned the car on again, put it into drive, and I was off with no problem.

I get to the stoplight, and with the car in drive and stopped, the revs went down real low again and the engine began to sputter and stalled. I turned it on again and proceeded to take off.

I get onto the expressway and the car seems to be running fine, but it seems to want to give itself gas. It will accelerate slowly by itself to about 60 mph, and will just stay at 60 without using the gas at all. My cruise control was NOT on, and hitting the brake does not cause it to want to get back up to 60.

In a nutshell, my car stalls at low rpm while in drive (not while in neutral), and also seems to accelerate on its own, almost like cruise control is activated. This hasnt gone away, and is repeatable.

What do you guys think is causing this?

Thanks much, Josh.