3L hates sitting still, confused

[nicasin717]

2004 edge 3L manual (probably from cali) , started out with a miss fire on #4 (if i remember right) So i changed all plugs. Still miss firing, so i changed wires, then coil pack...still miss firing.

It only happens if its idling, but if i push on the gas so it sits around 1500 - 2000 rpms it doesn't seem to miss fire (the truck will start shaking pretty bad when it does) the idiot light will flash at me, and probably 40% it will stay on, but most the time after i start going it goes away. Runs great when i am moving.

Changed the CRANKSHAFT sensor, still nothing.
So this morning i changed the CAMSHAFT sensor, still does the same thing. I guess my next step would be the synchronizer? seeing how i have already spent a few hundred $ i would rather know for sure what is wrong with this thing.

Anyone have any idea? Oh and when it is cold it doesn't seem to be as bad as when it warms up. getting to the point where im looking for a cliff to park it at and "forget" to put the brake on.

 

[RonD]

Reads like a lean fuel injector on #4, could be just dirty pintle(tip) run some SeaFoam in gas tank to clean it.
What does #4 spark plug look like compared to #5 and #6, cleaner would be a sign of leaner.
Swap injector on that bank, i.e. swap #4 injector and #5 injector and see if miss moves to #5, also inspect injectors when out
Vacuum leak on lower intake near #4 would also cause this.

On warmed up engine if you disable coil(unplug connector) then crank engine, then pull out #4, #5 and #6 plugs and check for how much fuel in on each you may see much less on #4.

Misfire is spark, fuel ratio or compression.
The mid-2000 3.0l's did have a valve seat issue, exhaust valve seat would recess when heated causing lower compression and misfiring.
Warm compression test of #4, #5 and #6 might yield some info on that.

 

[bg@f.ord]

do a compression test