The car ended up stuck in this long loop of "too slow, too slow, more gas more gas more more mooooOOOOH CRAP TOO MUCH TOO MUCH OFF OFF OFF WAY Ooooh that's better, much better this is nice, I'm right on, wait, no no no wait too slow, too slow more gas more more MOOOOAAAAHHHH TOO FAST TOO FAST..." which could sometimes last for miles, unchecked.
I had that happened to me when the fuel regulator for my car decided to go out. Line pressure leveled out once I got up to 65MPH. Slower than that it was all over the place. Drove straight to the mechanic to get it fixed.