QuestionI believe it is called Hyundai Accent in the US. It is a 1997 X3 SOHC. Idling is smooth. But whenever I pull off on a standing start and say give it a quarter throttle, the car would struggle and lugging. Sometimes it sputters on the tailpipe. It seems to get a little better when the car is warm. Funny thing is if I only give it a very light throttle, the car would gain speed smoothly, no struggling, no sputtering. So far I have changed the plugs, leads, air filter, fuel filter, new battery, oil change, auto transmission flush. Any idea on what the problem is ? Thanks in advance.
AnswerSince you specifically mention sputtering, I suspect you have a misfire issue. Most misfires are caused by secondary ignition components. Since you've already replaced the plugs and wires, you should probably check the ignition coil. U.S. models don't have a distributor, but if you have one on your vehicle, you should also check the distributor cap and rotor.
If the ignition components are functioning normally (and you have fuel injection), you should probably next check the fuel pressure. Although the symptoms don't exactly match what I'd expect, a weak fuel pump does tend to create a lack of power or misfire that becomes worse the more the accelerator is depressed.
