TEST 2: Testing For Spark Directly On The Coil Tower
Proceed with this coil pack test step only if you got a no-spark result from only one spark plug wire in TEST 1.
In this test step, you're gonna' test for spark directly on the ignition coil pack tower that connects to the spark plug wire that did not spark in TEST 1.
This test will help you to find out if the spark plug wire is bad and causing the misfire code or misfire condition on your 3.3L or 3.8L Chrysler car or mini-van.
- 1
Remove the spark plug wire that did not fire off spark from the ignition coil pack.
- 2
With a small piece of vacuum hose, connect the HEI spark tester to the ignition coil tower (see photos in the image viewer).
- 3
Ground the spark tester with a battery jump start cable to a good engine Ground point or directly on the battery negative (-) terminal.
- 4
Now, while you observe the spark tester from a safe distance, have someone crank the engine. The engine may start, so be careful.
- 5
You'll see one of two results on the spark tester: spark or no-spark.
Let's take a look at what your test results mean:
CASE 1: The spark tester sparked. This result lets you know three things: 1.) That the ignition coil is good. 2.) The spark plug wire is bad. 3.) The spark plug wire is the one responsible for the misfire or rough idle condition.
If you tested all of the spark plug wires in TEST 1, then no further testing is required. Replacing all of the spark plug wires as a set will solve the misfire or rough idle problem.
CASE 2: The spark tester DID NOT spark. The ignition coil is bad. Replacing the ignition coil will solve the misfire condition and the misfire code lighting up the check engine light (CEL) on the instrument cluster.
TEST 3: Testing For Spark Directly On The Coil Tower
Continue with this coil pack test step only if you got a no-spark result from two ‘Paired Cylinder’ spark plug wires in TEST 1.
A no-spark condition from two spark plug wires that feed two ‘Paired Cylinders’ usually indicates that the ignition coil pack is bad on your 3.3L or 3.8L Chrysler car or mini-van and this can be confirmed by first eliminating the spark plug wires as the cause of the no-spark result.
This test will confirm that either the spark plug wires are bad and the cause of the problem or that they are good, so you'll need to:
- 1
Choose the first spark plug wire (of the two that did not fire off spark in TEST 1) that you want to test and disconnect it from the from the ignition coil pack.
- 2
With a small piece of vacuum hose, connect the HEI spark tester to the ignition coil tower (see photos in the image viewer).
- 3
Ground the spark tester with a battery jump start cable to a clean and unpainted metal spot on the engine or directly on the battery negative (-) terminal.
- 4
Once everything is set and ready, have your helper crank the engine. Be careful and take all necessary safety precautions, since the engine will be cranking and may start.
- 5
You'll see one of two things: spark or no-spark.
Now, repeat these test steps on the other ignition coil tower that belongs to the other spark plug wire that did not spark in TEST 1.
Let's take a look at what your test results mean:
CASE 1: The spark tester sparked on both ignition coil towers. This result lets you know three things: 1.) That the ignition coil is good. 2.) The spark plug wires are bad. 3.) That the spark plug wires are the ones causing the misfire or rough idle condition.
If you tested all of the spark plug wires in TEST 1, then no further testing is required. Replacing all of the spark plug wires as a set will solve the misfire or rough idle problem.
CASE 2: The spark tester DID NOT spark in only one coil tower. This tells you that 1.) The ignition coil pack is fried and 2.) That the spark plug wires are bad.
Replacing both the ignition coil pack and the spark plug wires will solve the misfire or rough idle issue on your car or mini-van.
CASE 3: The spark tester DID NOT spark on both coil towers. This normally means that the ignition coil is bad but, I suggest doing one more simple and easy test. The next test is to make sure that the fuel injection computer is activating the particular ignition coil, within the coil pack, that did not fire off spark on its two towers.
- If you got NO spark from the towers that feed spark to cylinders 1 and 4, go to: TEST 5: Switching Signal Cylinders 1/4.
- If you got NO spark from the towers that feed spark to cylinders 2 and 5, go to: TEST 6: Switching Signal Cylinders 2/5.
- If you got NO spark from the towers that feed spark to cylinders 3 and 6, go to: TEST 7: Switching Signal Cylinders 3/6.
