I got in my car today after getting something at a gas station. I turn the ignition on and start the car. As soonas the car started up it started up rough as hell and made the car shake. Never done this before. What could it be? Spark plugs?
Did you get gas? One time I accidentally bought half a tank of 87 octane. After running it empty I switched back to 93 octane. The engine vibrated very strongly on startup. That is the only time it's ever done it.