At steady cruising speed no problems. Under light acceleration from say 35 to fifty it misses on number 1. Under heavy acceleration it misses and SES lights up.

Tried power braking it no miss.

Have replaced fuel injector and spark plug. It is a little better no light this time.

If I replace the coil and still have the same what is the next step. Engine sounds fine mechanically.

It does seem to get worse after it gets to normal operating temp.

 

Do the coil and go from there. I'd bet it is the coil and you won't need plan B.

 

Thanks I'll give it a try.

 

I had a similiar thing happening on my 03, but mine never would trip the CEL. Took it to my Ford garage, ended up being #7 plug was cracked and bad #7 coil. Replaced both, runs great again.

 

Replaced coil. Same symptoms.
Hold steady speed and it does fine. Running in OD and lightly touch
pedal it stumbles. Mash it hard and it misses and all of a sudden it takes
off fine up to 80 and now it does not miss.

I wish cars were as easy to diagnose as they used to be.
Any other ideas will be appreciated.

It did start missing at idle this morning.

Would EGR or TPS be a candidate for causing any of this?

 

Does not seem to light CEL now that plug, injector and coil have been replaced. Engine has good power when not missing.

 

If your plugs are in good shape, this is a common symptom of a weak coil, in OD when you level out the gas pedal, the tps reads a steady reading turning on the egr system, this introduces inert gas to the cylinders for cooling purposes, the timing is adjusted as well as the fuel, weak coils show there face usually when the engine is at hot, the spark is too weak to fire this mixture, and the pcm doesnt see this as a hard miss, no codes, look for signs of hairline cracks on tops of coils, or run a scanner live to see firing, usually when a coil goes out, others are not far behind, depending on how bad the bucking is you could have more than one weak coil, mashing on the gas pedal down shifts your trans from OD to 2nd gear, turning off egr and changing fuel and timing hence no miss

My .02

 

I'd hit the rest of the coils.

 

try the fuel filter also. they get dirty a lot on these trucks. also listen for vacuum leaks. I would suspect a coil,plug or injector.