How To Troubleshoot A No Start (Honda 3.0L)

A cranks but does not start condition, on your 3.0L V6 Honda Accord or Odyssey, can have you pulling your hair out since one component out of a bunch can fail and be the cause of the problem, for example you could have a:

• Broken timing belt.
• Bad fuel pump.
• Bad ignition coil.

The list goes on, but you get the idea. In this tutorial, I'll go into the basics you need to know to successfully diagnose a cranks but does not start condition.

You can find this tutorial in Spanish here: Cómo Probar Un Arranca Pero No Prende (3.0L Honda Accord y Odyssey) (at: autotecnico-online.com).

Difference Between A No Start And A No Crank Condition

Before we jump right into the basics of what causes a no-start condition, I want to clarify the difference between a no-crank and a no-start since they're not the same thing and knowing the difference will speed up your diagnostic.

Here's a brief description that'll help you make sense of this tutorial (and will help you find even more info online):

Cranks But Does Not Start Condition: This condition is also known as a no-start and it means that your Honda's starter motor is cranking the engine but the engine is not starting. This is usually due to a fault in the ignition system, or in the fuel system, or there's an engine mechanical problem (like a thrown rod, etc.).

Does Not Crank Condition: This condition is also known as a no-crank and it means that the engine is not cranking when you turn the key to crank the engine. In other words, the engine doesn't turn over at all. This is usually due to a bad starter motor, bad ignition switch, bad neutral safety switch, or the engine is locked up.

If your Honda doesn't crank and you suspect the starter motor, here's a tutorial that'll help you test it: How To Test The Starter Motor (Honda 3.0L).

No Start Condition Basics

Knowing the three things the engine needs to start is the key to successfully diagnosing the no-start condition your Honda is experiencing. These three things are:

1. Air.
2. Fuel.
3. Spark.

This means that if our Honda doesn't start, then we need to focus on finding out what's missing. Usually either spark will be missing, or fuel will be missing, or the engine doesn't have compression (think broken timing belt). It's as simple as this! I know, I know, I may be over-simplifying it all but knowing that only one of three things is missing really helps to put the problem into perspective!

To get down into the nitty-gritty details- this means that troubleshooting the problem requires that you or I check for spark (with a spark tester), check fuel pressure, and if necessary, check the engine's health with a compression test.

I'll go into more specific details in the following headings:

1.)  Ignition System

1. The ignition system is the one tasked with creating and delivering spark to each of the 6 cylinders. Without spark, the engine will crank but not start.
2. The ignition system of the Honda vehicles covered by this article use either distributor type system or a COP (Coil-On-Plug) ignition coil system. In a COP ignition coil system, each cylinder has its own ignition coil; thus eliminating the distributor entirely.
3. In my experience, the most common component failures, of the ignition system that cause a no-start no-spark condition are:
   • Ignition control module (ICM) -most commonly known as the igniter (if distributor equipped).
   • Ignition coil.
   • Distributor cap (if distributor equipped).
   • Distributor rotor (if distributor equipped).
4. All of the above ignition system components can be tested in a methodical way to find out exactly what has failed (if indeed something has).

2.)  Fuel System

1. The fuel system is the one responsible with supplying the engine with fuel.
2. The fuel system component that causes the majority of no-start no-fuel problems:
   • Fuel pump relay.
   • Fuel pump.
3. The fuel pump can be tested to make sure it has really fried using a fuel pressure gauge.

3.)  Engine Mechanical System

1. The components that are responsible for drawing in the air the engine needs are the: engine pistons, cylinder head valves, and all the other related components like: timing chain, etc.
2. Although rare, internal engine mechanical problems can and do cause no-start conditions.
3. Possible internal/external engine problems are:
   • Blown head gasket.
   • Blown engine.
   • Busted timing belt.

OK, the list of possible things that can go wrong looks pretty long but it is rare to see (or have) two different components go bad from two separate systems at the same time.

The cool thing is, is that there is a diagnostic strategy that you can use to figure out exactly what's wrong with your particular no-start problem. Let's find out more about it in the next subheading.