I will start my car and begin driving. Generally after about 5 minutes, the engine begins to run really rough. If you slowly press on the accelerator it starts to really buck. Most always, it does it when it's cold, but occasionally it will do it after it has warmed up and I have stopped and turned off the car. I have found that putting it in neutral, while driving, and turning off the ignition for a few seconds, then restarting the engine, will usually stop it from doing it, until the next time when the car is cold. no warning lights come on when this happens. I have had a mechanic look at it. He put a distributor cap on, but that didn't solve it. Also when it hapens, if I put the car in neutral and rev the engine, it runs smoth, but when I put it back in gear, it will start again, until I turn it off and restart it.