When at operating temp engine stumbles momentarily at part throttle.
It's like a buck more than a misfire, no check engine light either.
I have 120,000+ miles on truck, only repairs ever needed so far was the camshaft synchro and sensor (Motorcraft parts) about 2 years ago, oh and the brake pads were replaced at about 110,000 miles (the original ones!).
My symptoms are very similiar to folks who have faulty DPFE, but I have
learned my year of vulcan does not have one.
Any ideas? Truck runs ok otherwise.

 

My 2005 3.0 Vulcan had a similar problem. It turned out to be a burnt coil pack. If one goes, it kills two cylinders. Pull the wires off the coil one at a time and see if anything looks burnt.
2005 Ranger Edge 3.0 Vulcan, auto
only 50K miles!

 

brolinger, it had a bad coil pack and did not emit an error code?

 

It's been a few years, but I think I recall that the idiot light did come on. The mechanic said that the factory missed putting dialectric grease on the plug wire/coil socket that burned.

 

I put a new motorcraft coil pack in Sunday and so far the stumble is gone.
So thanks Brolinger. The old coil pack had some very fine cracks on the outside of it,
bottom looked brand new still. Hopefully that was it!

 

Glad my tip seemed to do the trick. Mine was burnt, yours was cracked. Same result. Have you replaced the plug wires in recent years?