Truck's running like a dog at times. I'll get misfires in every cylinder except #1 and at other times no misfires at all. Any thoughts about a cause? Haven't taken it to dealership b/c I'll need to change some things back to stock, but would like to figure it out on my own. Thinking coils, but that many at once is odd. Already have new plugs and wires.
Thanks for your help.
Paul

 

That's how my problem started. Now I'm taking it to the shop. It clatters as bad as a powerstoke in the morning. This is not that normal morning tick, this is down right embarassing. I'll post whatever I find out. But they are going to have to tear it down I'm sure.

 

Any codes being thrown?

I recall seeing a TSB about some misfire codes, I can look it up to see what the problem related to.

The only misfires that I ever detect seem to be when I am sitting at idle in "D" at a stop light and every so often you can feel a shudder both in the gas pedal and in the whole truck itself. It almost seems to follow a pattern as well. Anyone else get that one?

 

Only thing I could come up in the TSBs was a misfire problem which is caused by water entering the fuel system via the EVAP cannister solenoid.

 

[quote]Originally posted by ZBass28:
<strong>Any codes being thrown?

I recall seeing a TSB about some misfire codes, I can look it up to see what the problem related to.

The only misfires that I ever detect seem to be when I am sitting at idle in "D" at a stop light and every so often you can feel a shudder both in the gas pedal and in the whole truck itself. It almost seems to follow a pattern as well. Anyone else get that one?</strong><hr></blockquote>

P0300--which is multiple cyliinder misfire

Mine also does the shudder thing in "D" at idle.

 

P0300 is the code listed in the TSB that gets set when the water in fuel problem is present. Obviously it will set that code on any misfire problem, but it may be something you may want to look into. It would also be a warranty issue if it is.

Has it been raining heavily where you are lately?

 

[quote]Originally posted by white53gmc:
<strong>Any thoughts about a cause?</strong><hr></blockquote>

Crankshaft Position Sensor?

 

[quote]Originally posted by ZBass28:

Has it been raining heavily where you are lately?[/QB]<hr></blockquote>


It's been raining, but not heavy, just steady.