[JRTJH]

There was a time when engines had carburetors, fast idle cams, acceleration pumps, chokes and jets to adjust the mixture. Those days are long gone for the automotive industry and fast becoming dinosaurs even in the small engine world. Check out the latest Stihl chainsaws, "electronic control"....

Anyway, with EPA doing what they do and the automotive emissions controls being what they are, everything has changed from the "old style" push the accelerator to the floor, slowly release it (to set the fast idle and choke) and start the engine. It'll stay in fast idle until you "tap the accelerator"... Back then, if the engine "skipped at bit during warmup" you could set the choke a tad richer, increase the fast idle cam setting, retard the timing a touch or sometimes, just tighten the air cleaner cover after wiggling it a bit on the carb mount..... Those days are long gone... Now the computer won't let you make any adjustments to parts that are no longer even used.

Today's "comupter managed engines" are designed to run at the lowest RPM, leanest fuel settings and greatest timing advance without engine damage... Note, that's NOT the same as the "nicest setting for smooth operation"....

I'm certainly no expert, but I'd suspect that the way your engine is operating is "within the normal engine specifications" (the +/- range) and Ford will probably suggest there's nothing out of tolerance so no warranty repair...

Possibly, there's an "engine management software update" ??? Otherwise, I'd suspect it's more a situation where your specific truck was "built with two or more components that are within the +/- specs on the low end and when those two components are "in a matched set" the computer management "magnifies their specific minus end (or positive end) of the tolerance band" and the result is a "one second skip during warmup" and only occurs when the computer senses the output of the "first low end tolerance component" when compared to the "second low end tolerance component".... It's all part of that "lowest possible fossil fuel burn" computer program.