Engine Performance problem
1999 Nissan Altima 4 cyl Two Wheel Drive Manual
code read misfire #4 cylinder. Plugs, wires cap everything has been replaced. Could this be an injector and if so how do you check to see if injector is firing correctly. Car runs good but just a little sporatic idiling. Rpms bounce around while at an idle
Engine misfiring can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.