TEST 2: Testing For Spark At The Distributor Cap
In this test, we're gonna' see if the spark plug wire or wires that did not spark in TEST 1 are bad (or not).
We'll accomplish this by bypassing the non-sparking spark plug wire and testing for spark directly on the spark plug wire's distributor cap tower.
IMPORTANT: This test is only for when one or several (but not all) of the spark plug wires did not spark!
Remove the spark plug wire that did not spark from its tower on the distributor cap.
Place the spark tester directly on the tower.
Ground the spark tester with a battery jump start cable (which will also hold the spark tester to the tower as shown in the photo at left).
Have your assistant crank the engine while you observe the spark tester.
You're only gonna' get one of two results: Spark or No Spark. Let's analyze each of these results below:
CASE 1: You got spark. Then the spark plug wire is bad, replace them all. This is probably as far as you may need to go since your Honda Accord, or Civic or Odyssey will probably start after replacing these parts.
Here's why: As the spark plug wire ages, its normal resistance to spark increases to the point that the wire can not and does not transmit the spark to the spark plug. This will either cause a misfire, or a lack of power, or a no start condition. spark plug wires don't last forever, especially after-market ones (average life-span is 3 to 4 years).
CASE 2: You got No Spark. Then the distributor cap is probably bad. I say probably because further testing is required. TEST 3 will help to further test the distributor cap.
Here's why: As the distributor cap ages, the terminals that transmit the spark to the spark plug wires corrode. This corrosion increases the resistance to spark and over time (as more corrosion is created) this same corrosion stops the spark from passing thru' to the spark plug wires. The good news is that this condition CAN be tested. Go to: TEST 3: Testing For Spark At The Ignition Coil.
TEST 3: Testing For Spark At The Ignition Coil
Honda distributor caps do go bad and when they do, they end up causing a rough idle condition or a no start condition.
Thankfully, you don't need to replace the cap to see if it's bad (or not).
Depending on the result of this test step, we're gonna' find out if the distributor cap is bad (or not).
IMPORTANT: This test requires that the ignition coil be tested with the distributor cap off of the distributor. It's important that this test be done with a spark tester attached to the ignition coil. The car cannot/should not be cranked without the ignition coil being grounded by a spark tester (thanks to Randy for the feedback).
You can see this specific test step done here in this youtube video (although it involves a 2.0L Honda CR-V, the test steps are very similar): How To Test The Ignition Coil (1999-2001 2.0L Honda CR-V).
These are the test steps:
Remove the distributor cap and place the spark tester directly on the ignition coil's tower (as shown in the photo on the left).
Have your helper to crank the engine once again while (1) you watch for spark jumping across the air gap of the spark tester and (2) that the distributor rotor is turning.
You're gonna' get one of the 3 results: (1) spark and the distributor rotor turns or (2) No spark and the distributor rotor DOES NOT turn or (3) No spark and the distributor rotor DOES turn.
Let's analyze each result in more detail below:
CASE 1: You got spark & the distributor rotor turns. Then the distributor cap and/or distributor rotor is/are bad, replace them both.
Here's why: This test confirms that the ignition coil is producing spark and therefore is good. In a good working distributor cap, this spark is transmitted to the rotor by the cap itself. The distributor rotor in turn, transmits it to each terminal inside the distributor cap. Now, since in TEST 2, you've confirmed the cap is not transmitting this spark to the Wires, so then this spark result (from the ignition coil) lets you know beyond a shadow of a doubt that the cap is bad. Do not proceed to TEST 4, or TEST 5, or TEST 6.
CASE 2: You got NO spark and the distributor rotor DOES NOT turn. This is the result of a timing belt that has broken. Another cause, that I've seen quite a bit, is that the camshaft has broken in two, although this doesn't always results in a broken timing belt. Inspect the timing belt and/or remove the valve cover to see if the entire camshaft is rotating as one piece.
Here's why: The crankshaft rotates the distributor rotor via the timing belt. How? Well, the distributor is physically connected to the camshaft. The camshaft is rotated by the crankshaft via the timing belt. A broken timing belt won't rotate the camshaft and by extension, the distributor rotor. And if the distributor shaft does not rotate, the computer will not receive the Position Sensor Signals and the ignition system will not work to produce spark.
CASE 3: You got NO spark and the distributor rotor DOES turn. Then further testing is required to see if the problem is due to a bad igniter (ignition control module) or a bad ignition coil.
Your next step is to make sure that both the igniter and the ignition coil are getting power (12 Volts). Go to:TEST 4: Making Sure The Ignition Coil And Module Are Getting Power.