Hi. Im tryin to learn as much as i can about engines, and the trucks themselves. I have a 99 f-150 4.6L, so far so good. I have a friend who has a silverado, and he said it was misfiring. What is misfiring? and how can you tell if your truck is doing it? thanks

 

I'm not familuar with GM PCM handling of the missfire monitioing, but they should also set code from their misfire routines.
This function is dictated by the federal EPA for all mfgers.
If you want to learn about all the OBDII concering Ford, visit the Motorcraft site and down load the info for study.
The Ford handling of missfire is very complex and becomes a stumbling point for the 'do it your selfer' because he has no realization of the complexity.
EGR systems have changed over time and are year dependent on what system is being used.
This is one big reason there are so many different PCM base codes.
Self education can be done as long as you have a reasonable base of understanding to understand what you are reading.
Good luck.

 

General motor vehicals are so easy to find a misfire. Just plug in the scanner and pull up the chart. It will show current and history misfires. Tim

 

Misfiring is usually associated with a rough idle or an audible "miss" in the rythm one hears at the exhaust pipe. That "miss" in the rythm is a cylinder that is not firing, whose plug is being fired by another cylinder's spark due to faulty spark plug wires (out of sequence without fuel load in the cylinder), or a cylinder with a bad plug.

Another reason for miss may be the fuel supply; if water is in the fuel, obviously, the cylinder will receive water vapor at the injector, for example, instead of fuel vapor. That cylinders energy will not be equal with the cylinder that received a full fuel-vapor charge and will, consequently, miss.

I'm sure there are other things that contribute to miss. I'm sure if I missed any, someone will fill in the blanks.

Hope this helps,
Curt

 

Schwinnmb3.

Yes, the misfire counts and history are easy. If you have a Tech2.

Mark