Troubleshooting starting problems on a Ford Ranger is necessary when you can't start the vehicle. The problem isn't always obvious, so you'll need to consider a variety of issues. The starter motor could be weak or faulty, the battery could be dead, or you could have a flooded engine or no spark.
Crank the engine. If the engine cranks faster than normal and won't start, then your starter is likely failing and requires replacement by a professional mechanic.
Check for a flooded engine. Crank the engine. If it cranks normally, and if there is a strong fuel smell in the engine bay but no fuel leaks, then your engine may be flooded with gasoline. This is symptomatic of an air-to-fuel mixture problem. Probable causes are a bad mass air flow sensor or a sticking throttle valve. The entire intake system should be cleaned by a professional mechanic.
Pull a spark plug wire off the top of the engine. It should pull right off, but you might have to wiggle it a little as you are pulling up on it.
Remove the spark plug as follows. Attach the spark plug socket to the extension and lower it into the spark plug well. Turn the spark plug counterclockwise to loosen and remove it.
Pull the spark plug out of the plug well and remove it from the socket. Insert the spark plug into the end of the spark plug wire so that the electrodes are facing out (the orientation is the same as when the spark plug was in the engine).
Crank the engine and have an assistant check for spark on the spark plugs.
Repeat Steps 3-6 for each spark plug. If there is no spark on any of the plugs, then your problem is a bad spark plug, plug wire or distributor. To verify whether the problem is the plugs and wires, remove the plug wire at the distributor end and crank the engine. You should see a small, but solid, blue spark jump to a metal part of the engine. If there is no spark, then you need to replace the distributor. If there is a spark at the distributor, then you'll need to replace the spark plugs and wires.