So I got crazy and bought a '94 Ranger XL RWD Manual with the 2.3 and 330K miles on it. Body looks decent for it's age but the engine- well it's running fairly rough. The previuos owner replaced the plugs & wiring- he wired it with the standard firing order...

back
3-1
2-4

4-2<
1-3<
front
But it is idling pretty rough and on several YT vids I noticed some enthusiasts are switching the firing order on the front 4- numbers 2< &3<. So having little to lose I thought I'd try it just to see how it ran- and it's running a lot smoother. What's the skinny on that?

 

Welcome to the forum

Sorry for the background on your spark system but you need to know some of it to know what swapping around spark plug wires means

Your dual spark plug engine can run on just 4 spark plugs, it did just that from 1974 thru 1988
Your 2.3l Lima engine got dual spark plugs in 1989 when it went distributorless, to give it a bit more power
There is NO alternating of spark plugs, there would be no point of having dual spark plugs unless BOTH sparked at the same time

Each of your coil packs only has 2 coils inside, so 2 spark plugs are on one coil, they both spark at the same time, its called a Waste Spark system, very first spark system invented in the late 1800's, and works quite well, spark at every TDC of each piston/cylinder

Unplug the 3 wire connector on either coil pack
Start the engine
Should run smoothly, if not then one or two spark plugs on the working coil pack is not working

shut off engine and reverse it, plug back in a coil pack and unplug the other
Same test

This will tell you if your wiring will work as is

To balance any multi-cylinder engine there needs to be Matched Pairs of pistons
On the 2.3l Lima the Matched Pairs are 1/4 and 2/3, this means pistons 1 and 4 are at TDC(top dead center) at the same time, and 2 and 3 are at TDC 180deg later
This balances the rotating mass of the engine
The firing order is 1 3 4 2
You can see the Matched pairs in any firing order by splitting it in half and put one above the other(this works for V6, V8, V10 engines as well)
1 3
4 2

Look familiar

1 and 4 will Always be on the same coil on either coil pack, doesn't matter if its 1 4 or 4 1 they both spark at the same time, so reversing these doesn't matter
2 and 3 will be on the other coil in the pack, again 2 3 or 3 2 doesn't matter

The 3 wire connection matters, the center wire is 12volt power for both coils, each outside wire controls the coil on that side of the coil pack
Outside wire matters because it can be for 1/4 or 2/3 spark, but spark plug wires can be 4/1 or 3/2 respectively that part doesn't matter
1 4
.....] <<<connector
2 3


Do the test and run the engine on just one coil pack to make sure all 4 spark plugs on that pack are working as they should
Then test other coil pack
You should do this test once a year
The downside of Dual spark plugs is that the driver would never know if one spark plug had failed because the other spark plug is working, but there would be a slight loss of power


1994 can have a Spark inhibitor circuit for the intake side spark plugs, so coil pack for those spark plugs won't spark when starter motor is active, but I think 1992 was the last time that was used on the 2.3l dual spark
This was done to give exhaust side coil pack more voltage for cold starts, but was found to not be needed