Mechanics

ENGINE MISFIRE

2001 Ford Ranger

Engine Performance problem
2001 Ford Ranger 6 cyl Two Wheel Drive Automatic 95000 miles

When Im driving on the highway doing about 60 or so my truck starts shaking then my check engine light comes on and starts flashing if I slow down to under 60mph it goes off. The other day it stayed on solid so I took it to have the diagnostic error code read what up is PO302 misfire at cylinder 2. What could be causing this the truck seems fine when Im not driving faster than 60?
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Ranger78
January 12, 2010.



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.

P0302 Cylinder misfire at No.2-you should check the sparkplug, compression and injector for this cyl.

Rasmataz
Jan 12, 2010.
Well spark plugs wires coil egr valve are all less than 5 months old

Tiny
Ranger78
Jan 12, 2010.
What do you think is the most likely cause since it only occures when Im driving faster than 60mph?

Tiny
Ranger78
Jan 12, 2010.
There's other things involved here such as 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

Rasmataz
Jan 12, 2010.