sputtering really bad. crazy idle please help

[poultry180sx]

i have a 93 240sx auto. ka motor. the car has only stalled once on me ever. the problem is that the car is sputtering really bad and the motor is shacking like crazy, and the muffler sounds like crap. the last time i drove it it was fine. i just filled it up and didnt drive it for about 3 days. got in the car and started it and that what i got i have no idea what it could be. it also has a new water pump and spark plugs. please help thanks alot.

[ngibson]

If it sat for that long, could have had crappy gas with junk that settled. I would start by checking your ground wires (a lot of sputter / hesitation is caused by a loose ground), maybe vacuum lines.

What octane gas do you use? Even try siphoning the gas out, fill up again with a higher octane / better gas station. I personally only fill up Mobil or Chevron and use only Premium.

Let us know if any of that works / what doesn't.

[nismo racer]

my car used to do that aswell, it was the spark plug wires. also have you checked the MAF?