Engine Performance problem
1998 Kia Sportage 4 cyl Four Wheel Drive Automatic 153, 00 miles
This vehicle starts fine but once you push the gas pedal to accelerate it dies or sputters. If you lightly push pedal sometimes it will run fine. I have replaced the spark plugs and wires, both coils, mass air flow sensor, and throttle positioning sensor. No change. Can you please advise what problem may be.
Possible causes could be one of the following: Oxygen Sensor
Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)
Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include: Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires
Coil and Rotor