Where do you start when you can not get a 2001 Ford Ranger engine to fire?

Answer 1

First I am believing that you have a good fully charged battery, a good starter, and NO Check Engine Light or any other red indicator lights on the dash WHILE cranking the engine.

Second, I am sharing my experience and thoughts only. You are responsible for the final outcome AND for being safe.

There are only 4 things needed to get any engine to fire. They are:

Fuel,

Electrical / Spark,

Air and

Rotation (for compression)

(FEAR)

MOST COMMON is a fuel problem.

1) Fuel is not reaching the cylinder because the pump is not pumping (electrical or mechanical), the fuel filter or something else (kink in fuel line) is blocking flow, the Carburetor or Injectors are dirty (though with FRESH fuel the engine should at least fire even if it won't run.

2) The fuel is contaminated due to

A) The fuel is so old it has changed chemically and begun solidifying (causing it to be gummy)

B) There is condensation (water) in the tank which has been delivered to the Carburetor or Injectors

C) There are other contaminates that have been introduced to the fuel tank (sugar for instance)

SECOND MOST COMMON is an Electrical / spark

1) SECONDARY Ignition system - If you have Fresh fuel delivery perhaps spark is not reaching the spark plug (there are in-line testers that are quite inexpensive and available at most auto parts stores) that should be used to test for spark while the starter is engaged. Some will say to unplug the spark plug wire and place the tip of a screw driver into the end of the wire and then hold the metal portion of the screwdriver close to the engine block while the starter is engaged (you should see a clearly BLUE spark)

NOTE: with today's High Energy Ignitions (HEI) there is a possibility of injury so I do NOT recommend this method of testing

2) PRIMARY Ignition system - If you are not getting spark, check other spark plug wires. If no spark plug wires are getting spark, then there is a problem with the Primary Ignition system

THIRD MOST COMMON is Rotation (to cause compression). If you have Fresh fuel delivery and sufficient spark then the next thing to check is the Compression. In my opinion, an engine CAN run (but should be repaired) with the compression as low as 75% of the recommended compression value (typically between 135-170psi). The important thing about compression is that the cylinders are EQUAL (within 10% though 5% is preferred). This ensures that the WHOLE engine is working in a balanced manner as designed. A four cylinder engine that has two cylinders at 160psi and two at 125psi means you basically have a 2 cylinder engine

LASTLY is Air. It has been my experience that an engine will run with a completely clogged air filter, BUT it will not run well at all.