2.5L ('98-'01) 2000 ford ranger 2.5l engine problems

[DCman]

Usually, you'd be right Mike, but every once in a blue moon, you'll run across a leak that occurs in the opposite manner.
Its not common, but it happens.

 

[tomw]

You are likekly running on all three.... Higher rpms cover the misfire to the point you don't hear/detect is, but the performance limits suggest you are not using the full four to produce power.
If you have a dead miss at idle, it is noticeable. Rev the engine, and it seems to 'go away'. It did not go away, it was just covered by other noises, and disguised by the fact the crankshaft is rotating faster. You may get some power out of a bad cylinder(valves/rings) as the cycle does not leave a lot of time for the fuel:air mix to leak out before the sparky tries to get it to burn. It may burn, but won't add a lot to the output power.
Have you done a compression test? Leakdown test? Those will tell the tale of mechanical problems. Fuel or ignition problems won't generally show on either test, so if the numbers are good, start looking at fuel & sparky.
tom