Hey, ‘dad. Which engine do you have in your truck?
When I tested the coil pack on my ’92 4.0, I did a Youtube search and got the info I needed (sorry that I can’t seem to track down the specific video I watched). You’ll need a voltmeter to do it, which I had. It’s not hard (I’m a total amateur with volt/ohmeters). Turned out that mine was fine, which saved me the expense of replacing it.
The way you describe the issue is kind of odd. Maybe the computer is messing up for some reason (I’m really bad with those)? Two members that I’ve found to be extremely knowledgeable and helpful on here are adsm08 and RonD. Maybe you can loop them in here?
Good luck, man!