You might think that troubleshooting an engine no-start problem is a difficult thing to do, but nothing could be further from the truth.
I can tell you from personal experience that there's a method to the madness of diagnosing an engine no-start problem. This tutorial will share how I diagnose and resolve an engine no-start problem. I think you'll find this information pretty handy!
NOTE: You can find the 4.0L Ford Explorer, Aerostar, and Mercury Mountaineer no-start tutorial here:
- How To Troubleshoot A No-Start Problem (4.0L Ford Explorer, Aerostar, And Mercury Mountaineer) (at: troubleshootmyvehicle.com).
Contents of this tutorial:
- Difference Between A No-Start And A No-Crank Condition.
- Engine No-Start Diagnostic Basics.
- What Tools Do I Need?
- STEP 1: Testing The Ignition System For Spark.
- STEP 2: Testing The Fuel Pump's Pressure.
- STEP 3: Making Sure The Engine Has Good Compression.
- STEP 4: Checking For A Blown Head Gasket.
- No-Start Troubleshooting Summary.
- More 4.0L Ford Ranger (Mazda B4000) Tutorials.
APPLIES TO: This tutorial applies to the following vehicles:
- 4.0L V6 Ford Ranger: 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011.
- 4.0L V6 Mazda B4000: 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009.
Difference Between A No-Start And A No-Crank Condition
There's a significant difference between an engine no-start problem and a no-crank problem.
Since this tutorial only focuses on an engine no-start problem, I'll explain the difference between both:
- In an engine no-start problem, you turn the key to start the engine, and the engine cranks but does not start.
- In a no-crank problem, you turn the key to start the engine, but nothing happens since the starter motor does not come out to play.
If your 4.0L V6 Ford Ranger or Mazda B4000 is experiencing a no-crank problem, your troubleshooting should start with the starter motor.
Engine No-Start Diagnostic Basics
As you're probably already aware, the engine needs three things to start. These three things are:
In plain English and for our testing purposes, this means that when the engine in your 4.0L Ford Ranger doesn't start, it's because of one of the following reasons:
- The engine isn't getting any fuel.
- The engine isn't receiving spark.
- The engine isn't producing any compression (this is the 'air' part).
This also means that we can perform four basic tests to find out what's causing the engine not to start:
- Ignition system test (spark test).
- Fuel system test (fuel pressure test).
- Engine compression test.
- Blown head gasket test.
The following sections will describe the step-by-step procedure I use to troubleshoot an engine no-start problem.
What Tools Do I Need?
You'll need a few essential tools to figure out what's behind your engine's no-start problem. But, don't worry, nothing in this list will break the bank.
- A spark tester.
- A fuel pressure tester.
- An engine compression tester.
- A multimeter.
- A code reader.
For the ignition system spark tests, I'm going to recommend that you use an HEI spark tester.
This is the most accurate spark tester that you can buy, and it doesn't cost an arm and a leg. You can find out more about it and where to buy it here: HEI Spark Tester (at: easyautodiagnostics.com).
You'll notice that I didn't include a scan tool in the list. But if you have one, I can tell you that it'll come in handy. Why? Because some of the components that cause a no-start condition can leave a specific trouble code (when they fail).
In this tutorial, I haven't included it (a scan tool) in any of the suggested tests because they can be done without one.
STEP 1: Testing The Ignition System For Spark
I've always started my engine no-start diagnostic tests with the ignition system spark test. So I'm going to recommend that you do the same.
The idea behind the ignition system spark test is to make sure that all six spark plug wires deliver spark to their spark plugs.
If all of the spark plug wires are not sparking, you can conclude that the ignition system is behind your 4.0L Ford Ranger or Mazda B4000's engine no-start problem.
You must use a dedicated spark tester to test the spark plug wires for spark. As I mentioned before, I recommend the HEI spark tester for the spark tester.
Any other spark test method that does not involve a dedicated spark tester will have you chasing ghosts. Worst of all, you'll end up wasting time and money replacing good parts that don't solve the problem.
The following ignition system test tutorial will help you get started:
The ignition system is NOT causing the no-start problem if:
- Spark is present at all 6 spark plug wires.
With all 6 spark plug wires delivering spark to the cylinders (spark plugs), you can conclude that the ignition system is NOT causing the engine no-start problem.
You can also conclude that:
- The crankshaft position (CKP) sensor is good.
- The ignition control module (ICM) is good (if equipped).
- The ignition coil pack is good.
Since the ignition system is creating and feeding spark to the engine cylinders, the next test steps are to test the fuel pump's pressure. Go to: STEP 2: Testing The Fuel Pump's Pressure.
The ignition system IS THE CAUSE of the no-start problem if:
- You got NO spark at all 6 spark plug wires.
The components that can cause this no-spark problem are:
- A bad crankshaft position (CKP) sensor.
- A bad ignition control module (ICM) -if equipped.
- In some rare cases, a bad ignition coil pack.
Your next steps are to:
- Test the crankshaft position (CKP) sensor.
- Test the ignition control module (ICM) -if equipped.