Engine Performance problem
1995 Ford Taurus 6 cyl Front Wheel Drive Automatic 120000 miles
Hello, about a month ago my car would have a really hard time turning over, and when it did have a hard time turning over, it would not run well. (Misfiring/hesitation) so, I replaced all plugs and wires, the fuel filter, PCV valve, the distributor cap, the rotor and the two O2 sensors. Then I changed the TPS, then cleaned the Idle Air Control Valve thoroughly. I sprayed cleaner to test for vacuum leaks, and got nothing. My coil definitely has a spark, I tested with my meter. I am stumped. Now the car shakes as if it is misfiring even at idle, and at cruising speeds. Especially when stopped at a stop sign or light. Please help!
Check the following: 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