My 2000 Ranger 2.5L with manual transmission is throwing a CYLINDER 2 MISFIRE code. My plan is to pull the number 2 cylinder spark plug and also look at the ignition coil.
The truck has two coil packs and 8 plugs. As I understand it one coil pack and a set of 4 plugs fires for the ignition, the other set fires on the exhaust stroke for emissions.
Can someone tell me which coil pack and set of 4 plugs is for the ignition. Thanks. Paul G

 

No, that's mis-information
Point of dual spark plugs is that it adds power to an engine, thats why racers used it and why Dodge Hemi used it

So BOTH spark plugs fire at the same time or there would be no point in having dual spark plugs

This engine(as 2.3l) has been used from 1974 to 1988 with 4 spark plugs and distributor, and ran fine
So you can run yours on just 4 spark plugs to test each coil/plug setup

Misfire can be spark, fuel or compression issue
Spark is LESS LIKELY to cause misfire on dual spark plug engine because BOTH spark plugs would have to stop working, if just one spark plug stops working you would have slightly less power, but no misfire

Unplug the 3 wire connector on either coil pack, pull connector back so it can't arc to coil
Start engine
Should idle smooth, no misfires
REV it, drive it, see if you have a steady misfire

Then plug that coil pack back in and unplug the other one
Same test

You can put ONE new spark plug in #2, and see if misfire goes away, its a long shot that BOTH spark plugs in one cylinder would fail at the same time, but..........................
When a spark plug does fail in a dual spark system, you WILL NOT KNOW IT, because the other spark plug is still working, and it can go like that for years, so you would only notice it when 2nd spark plugs fails

That's why its a good idea to do the one coil pack test yearly on a dual spark plug system, to see if a spark plug has failed, the only way to know

A compression test would be next since its a black and white test, and mechanical, so no intermittent BS
2.5l should run 165psi

If compression is OK then fuel injector


Ford uses Waste Spark on 1995 and up Rangers, distributorless ignition system used since the first single cylinder gasoline engines in 1890's
This means each spark plug will spark when its piston is at Top Dead Center, compression or exhaust stroke, so one spark is "wasted", its not for emissions, lol, its done because its just easier to use the crank rotation to spark cylinders than the cam and doesn't hurt anything
Waste spark often confuses people when they read about it, this is where the incorrect alternating spark thing came from for the 1989-2001 dual spark Lima engine
All single cylinder and most distributorless multi-cylinder engines use waste spark, just FYI

 

Thanks for the information. I will check the coils as you suggested.
Thanks. Paul G