The car is running, but when rpm is at 1500 the car starts to make a rub rub rub noise in the parked position and when drivin it will not stay at a certain speed, usually will start to jerk, and I have to down shift and rev the car and drive faster to keep from jerking.....HELP>>>>>>>>>>>>

 

How fast is the "rub rub rub" noise; does is change speed with RPM, and does it matter whether the clutch is in or out? Can you hear anything rubbing from a specific area of the engine when you stick your head under the hood? Tell us more info......

 

Sounds like a good description of a V8 with some lumpy ass cams.

 

Or a heavily ported rotary...
It sounds kinda weird, just revving it up higher and it goes fine? So, as long as you're accelerating the car runs fine, it's just when you try to hold a speed?

 

Did you just do a swap, and has the car ever run fine since it was done? It sounds like a wiring or sensor problem.. Does is sound like it's making that noice because of the way it's trying to run or because of some kind of friction??

 

well the car sounds like it will cut out at 1500 rpm but idles fine and will drive fine until I try to maintain a certain speed and try to stay at 40mph or something like that and it starts to jerk and I have to drive faster to run fine, but in all at 1500 it gives me a problem and after that it runs fine.....HELP

 

Check the map sensor, check vacuum hose to the FPR and possibly TPS, any codes at all?