What Tests Can I Perform To Find The Cause Of The Misfire Condition?
Your misfire diagnostic should start with first reading the Diagnostic Trouble Codes (DTCs) that are lighting up your check engine light (CEL) with a scan tool (Don't have a scan tool? Need a scan tool? Check out my recommendation: Actron CP9580 Scan Tool).
If your Nissan is misfiring, you'll have misfire codes stored in your Nissan's computer's memory (P0300, P0301, P0302, P0303, P0304) and these will point you to the cylinder or cylinders that are misfiring.
The following are my recommendations as to what to start testing first. Although you don't have to follow the list in that particular order:
STEP 1: As mentioned earlier, the first step is to Scan for misfire codes. This will help you to identify what cylinder or cylinders are the ones suffering the miss.
STEP 2: Around 80% of the time, a misfire is caused by something having gone wrong in the ignition system, the first tests you should do are to make sure all of the spark plug wires are sparking (with a spark tester). This will let you know if the misfire is due to a lack of spark in the specific cylinder that the misfire code is identifying.
STEP 3: Removing and visually checking: spark plug wires, Distributor Cap and spark plugs to check for wear and tear, Carbon Tracks, anti-freeze, oil contamination, etc.
STEP 4: If testing the ignition system tells you that the problem is somewhere else, then next steps are checking fuel injectors, compression tests, vacuum leaks, etc.
Finding the exact cause of the misfire dogging your 2.4L Nissan Altima or Xterra or Frontier is not hard. It does involve doing some tests and using/buying some tools but I can tell you that it won't be anything that'll break the bank. As for the tests, you'll find the links to them in the next page in the section: Where Do I Find The Test Articles?.
What Tools Do I Need To Test The Misfire Code(s)?
Without the proper tools, you won't be able to diagnose/troubleshoot those issues on your 2.4L Nissan car or pick up. Not only that, you are gonna' waste time and money replacing the wrong components.
Depending on what the root cause of the misfire is, you may need several tools. Most of these you can buy online, none of these will break the bank and I'll make some recommendations on them. Here's a guide to some of the basic tools that can be and are used:
- Ignition System Tests:
- Spark Tester.
- Test Light.
- Fuel System Tests:
- Noid Light.
- Fuel Pressure Gauge.
- Engine Mechanical Tests:
- Compression Tester.
Now of course, you'll also need basic hand tools like: screw-drivers, ratchet wrenches, sockets, etc. You'll also need a generic scan tool to retrieve the diagnostic trouble codes (DTCs) from the computer's memory (Don't have a scan tool? Need a scan tool? Check out my recommendation: Actron CP9580 Scan Tool).
Keep in mind that using the right tool for the job will save you time, frustration, and /or keep you from damaging the component that you're testing.