This tutorial will help you to test one or all of the fuel injectors on your Honda Accord (or Odyssey or Prelude) with a simple multimeter resistance test.
Now, it's rare for a fuel injector to go bad, but that doesn't mean it doesn't happen. When one goes bad, you're gonna' have a rough idle condition that may be hard to diagnose.
Contents of this tutorial:
You can find this tutorial in Spanish here: Cómo Probar los Inyectores de Combustible (Honda 2.2L, 2.3L) (at: autotecnico-online.com).
Here's a real life case study that you may find helpful:
Symptoms Of A Bad Fuel Injector
A bad fuel injector will cause your Honda vehicle to do one or more of the following:
- Engine will have a rough idle.
- Engine will misfire under load, especially when you accelerate your Honda Accord (Odyssey, Prelude, etc).
- Lack of power when accelerating your Honda.
- Bad gas mileage.
- If your Honda vehicle is OBD II equipped, you'll usually see a misfire code (P0300, P0301, P0302, P0303, P0304) lighting up the check engine light on your instrument cluster.
There are 3 main causes of a fuel injector failure:
- Fuel injector doesn't spray any fuel.
- Fuel injector sprays fuel, but not enough (clogged fuel injector).
- Fuel injector stuck on all of the time (as soon as the key is turned On).
This article focuses on the most common, which is when the fuel injector doesn't spray any fuel at all due to an internal short circuit.
What Tools Do I Need To Test The Fuel Injectors?
To test the fuel injectors in your 2.2 or 2.3L Honda Accord (Odyssey, Prelude, etc.) you don't need any expensive tools.
Here's a basic list of tools you'll need to test all four fuel injectors:
- A multimeter.
- You'll only be using the multimeter to check resistance (Ohms).
- If you need to upgrade or buy a multimeter, check out my recommendation: Buying A Digital Multimeter For Automotive Diagnostic Testing (found at: easyautodiagnostics.com).
- Scan tool.
- To actually test the fuel injectors, you don't need a scan tool (since a scan tool can't dynamically test the fuel injectors). But, having one makes the whole process easier since you're able to retrieve any diagnostic trouble codes (DTCs) stored in the PCM memory.
- Don't have one? Check out my recommendation: Abe's Scan Tool Recommendation.
- Pen and paper to write down your fuel injector resistance test results.
The Fuel Injector test
To get an accurate snapshot of the condition of the fuel injector or fuel injectors that you need to test, the engine in your Honda vehicle has to be warmed up. The key word here is warm. If the engine is hot (normal operating temperature), let it cool down for about an hour.
If the engine is completely cold... start up the car (or mini-van) and let it run for about 20 minutes. If your particular Honda is OBD II equipped and you have a scan tool, you can verify that the engine's temperature is hovering around 100° F.
Alright, here are the steps:
Although you may want to just test one fuel injector, I recommend testing all four of them on your Honda Accord (or Odyssey or Prelude).
So the very first thing to do is to disconnect all four electrical connectors from the fuel injectors.
Turn on your multimeter and select Ohms mode and with the multimeter test leads, probe the Male Spade Terminals of the first fuel injector you're gonna' test.
It doesn't matter what color test lead you use to test either of the two fuel injector male spade terminals, the polarity of the leads is not important when testing the resistance (Ohms) of the fuel injectors.
Now, after measuring the internal resistance of this first fuel injector, write down this Ohms value down on a piece of paper. You'll be using this resistance value to compare it to the other three in a few moments.
Don't forget to write down to what engine cylinder this fuel injector belongs to. You can use the image in the photo viewer as an aid in identifying the cylinders.
The average fuel injector resistance value will be about 5 to 7 Ohms . This values may not match what's on your car but this shouldn't worry you and you'll see why in the interpretation of your test results in CASE 1 below.
Let's take a look at what your test results mean in the next page...