No Start 3: Checking Engine Mechanical Condition
Checking to see if a loss of engine compression is the cause of the cranks but does not start condition is one of the most overlooked diagnostic tests.
As mentioned at the beginning of this article, the engine needs air to be able to ignite the fuel inside its cylinders and the basic components that provide this air are the piston rings and cylinder head valves.
Here are a few testing tips and suggestions:
- When performing an engine compression test, what you're looking for is an average compression reading of NO LESS THAN 120 PSI across all or the majority of the engine cylinders.
- If you have one or just two readings that are under 90 PSI your Nissan vehicle will still start and run, albeit with a misfire condition.
- The following tutorial will help you do a compression test:
- The following tutorial will help you do a timing belt test:
- How To Test For A Broken Timing Belt (Nissan 2.2L, 2.3L) (this test info also applies to the 1.5L, 1.6L Nissan engines).
No Start Summary
Testing the basics, which are:
- Making sure all 4 cylinders are getting spark.
- Making sure the fuel pump is working and the fuel injectors are spraying fuel (Noid Light test).
- Making sure all cylinders have compression.
Testing the basics is the key to saving yourself time and money because when the engine is not starting, it's usually to a lack of: spark, or fuel, or air (engine cylinder compression).
To check the basics, you need tools. There's just no way around it. One of the analogies that I've always enjoyed repeating, about doing a job without the right tools is like trying to eat a bowl of soup with a fork.
So besides knowing what to test, you need tools to do those tests. You don't have to spend an arm and a leg, since you can buy a lot of diagnostic tools that are tailored for the pocket-books of the serious do-it-yourself-er. Here are some of the basic tools you'll need:
- Fuel pressure gauge.
- Spark tester.
- Compression gauge.
Related Test Articles
You can find a complete list of tutorials here: Nissan 2.4L, 2.5L Index Of Articles. Below, is a sample of articles you'll find in this index of articles:
- How To Test The Starter Motor (Nissan 2.4L -Frontier, Xterra).
- Power Transistor Test & Ignition Coil Test 2.4L Nissan Altima (1993-1997) (at: easyautodiagnostics.com).
- How To Test Engine Compression (Nissan 2.4L, 2.5L).
- How To Troubleshoot Misfire Codes (Nissan 2.4L).
If this info saved the day, buy me a beer!