1993 Ford LX Stuttering/Lurching

Hey all, I searched through to archived questions and I didn't find an answer that seemed applicable. Sorry in advance if this is a repeat/common question.

I have a 1993 LX Escort and after driving for a seemingly random amount of time it will start to alternate between 750-1000 RPMs at idle. After it begins doing this the car will accelerate poorly and will Lurch hard at various speeds depending on the gear. 2nd Lurching is at 20-25 mph, 3rd learching is at mostly exactly 30 mph, and it hardly lurches at all in 4th or 5th although it will slightly around 30-35 mpg in 4th gear.

This problem began recently, and I'm at a loss. I replaced the fuel filter on a friends advice and that changed nothing. A friend had a similar problem in a Honda CRX, except he only had the idling characteristics not the lurching problem. I'm assuming it has something to do with either airflow or fuel, possibly a fuel pump?

Any advice is greatly thanked.