Since I'm a Computer Scientist, I can't but help but to use the same techniques on automotive systems that I use analyzing computer systems. I try my best to never make a change to an existing system unless I understand the repercussions of that change. For example, before changing a column in a database table, the most accepted practice is to determine how that change will affect, stored procedures, back up procedures, data access layer, business logic layer, reporting sub-systems, user interface …
This technique has allowed me to work with very large computer systems effectively. So why wouldn’t this approach also work with automotive systems? From my experience, it does work very well.
When I first started out, I leveraged Google to find web pages, forums, and technical articles to determine how to fix my automobile issues. But, I quickly found out that most people didn’t spend the time to learn the automobile sub-system with the issue. They just threw parts at a problem. I was so disappointed. I couldn’t believe real mechanics work that way.
Since I’m a DIY Mechanic, I didn’t have the formal background or training of an actual professional mechanic. Therefore, my first task was to study automobile systems, from the mechanical and electronic angles. The Resource Page on this web site lists many of the resources I have compiled over the years. The purpose of this web page is to compare some examples of good resources versus some examples of some poor resources.
Good Resource
Working on a No Start condition
From EasyAutoDiagnostics.com
Example One:
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Remember, you can not use a regular spark plug instead of a spark tester for the spark test and do not pull the spark plug wire
off of the spark plug either while your helper is cranking the engine (to check for spark). Ok, here's the test:
- Remove the spark plug wire from its spark plug.
- Attach the HEI spark tester to the spark plug wire.
- Attach the HEI spark tester to a good ground point, or use a battery jump start cable to attach it to ground (my preferred method).
- Have your helper crank the engine while you observe the spark tester.
- Repeat the test for all of the remaining spark plug wires on your Honda Accord (Civic, CRX, or Odyssey).
Let's take a look at what your test results mean:
CASE 1: If you got spark on all of the spark plug wires: This result indicates that the ignition coil and the igniter
(ignition control module) on your Honda Accord, or Civic, or Odyssey are functioning correctly. The No Start Condition's
cause does not lie in the ignition system of your Honda.
...
Not So Useful Resources
The issue is a misfire.
From some web site that I shouldn't reference.
Example One:
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$30 says it's the fuel filter!
just by coincidence....anyone? $30!
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Example Two:
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If you happen to have an ODB-II code reader, try resetting the CEL codes and then let it run for a few more days to see what happened.
If it does not fix the problem, consider looking into a new/replacement O2 sensor and then see how it goes.
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Clearly, the Good Resource example lists precise steps and helps you analyze the results of your test. Using this procedure, the exact issue will be found. In addition, this particular set of web pages starts off with a theory of operation for the sub-system you are about to test.
Unfortunately, the Not So Useful Resources does not describe tests and expected results. These examples just list guesses as to what to replace. This technique is what I consider hacking at a solution. Throwing parts at an issue can be quite expensive and time consuming. Also, during the installation of parts, other parts can be broken, vacuum lines, connectors, seals ...
For example, let's assume a car is running lean. A not so good forum might say to replace the O2 sensor (at least $30) or replace the Idle Air Control Valve (at least $100). Where if test procedures were followed, a disconnected vacuum line going to the brake booster would have been found, costing nothing to repair.
Please don't be a hacker. Well, if you are a hacker, you probably haven't read this far anyways. But, if you have, you have demonstrated that you want to properly diagnose automobile issues. I hope the resources on this web site and the videos on my YouTube channel help you on your journey to become a skilled mechanic DIYer.