Weird engine miss-fires? Fuel filter? Bad gas?

Okay, so I thought I would at least ask: My '98 6-lug 3.4 is "missing" at low revs, especially noticeable when cold, but not always. I originally thought the missing was something I was experiencing only at low temps and revs, but the missing continues at high-revs too: I can feel it shuddering when I'm standing on it between 3K and 4.5k rpms. When I say "missing," I mean several short, staccato misfires on the engine that are completely noticeable.

Or perhaps it's a clogged fuel filter. Does this make sense? Do fuel filters fail incrementally?

Ideas?

James

 

Is there a code for the misfire?

 

^^^^ this. Before trying to diagnose ANYTHING, check codes first.

 

I have 2 ignitors go bad on me and the truck did what you are describing... didn't throw a code either...

 

Well, funny you should ask...

About 12 hours after posting this, I get a pending trouble code: P0306... something is amiss with my 6th cylinder. So that makes sense. The truck recently turned 200K and I think it's about time for 6 new plugs, wires and coils, so I've ordered those.

What else? Even if that doesn't solve anything, the truck will thank me.

 

SAme code mine was throwing last year I believe. Ended up being a coilpack if IIRC

 

What does that mean? "if IIRC"?

 

IIRC=If I recall Correctly

 

Ah...of course. Thank you.