When a fuel injector on your 1.7L Honda Civic fails, its internal resistance changes drastically (due to the fact that its internal coil's windings have shorted together or have an open).
A fuel injector that has failed will cause the engine to misfire as it idles and as you accelerate it down the road.
Thankfully, testing the fuel injectors isn't hard and/or difficult since they can be tested by simply measuring their internal resistance (and comparing it to what the factory specification is) and I'll show you how in this tutorial.
Contents of this tutorial:
You can find this tutorial in Spanish here: Cómo Probar Los Inyectores de Combustible (2001-2005 1.7L Honda Civic) (at: autotecnico-online.com).
Symptoms Of A Bad Fuel Injector
A fuel injector, on your 1.7L Honda Civic, can fail in one of several ways. It either:
- Stops injecting fuel completely due to an internal short or open in its coil windings.
- It doesn't inject enough fuel because its clogged.
- It over injects due to electrical issues.
No matter how the fuel injector fails, the symptoms are pretty much the same ones. These symptoms are:
- Rough idle.
- Lack of power.
- Hesitation when you accelerate your Civic down the road.
- Misfire trouble codes (OBD II equipped only):
- P0300: Random Cylinder Misfire.
- P0301: Cylinder #1 Misfire.
- P0302: Cylinder #2 Misfire.
- P0303: Cylinder #3 Misfire.
- P0304: Cylinder #4 Misfire.
The focus of this tutorial is to see if the fuel injector's internal coil has failed (and thus causing the fuel injector to stop injecting fuel) but testing for a clogged injector isn't that much more complicated and I'll show you how in the next page.
Where To Buy The Fuel Injector And Save
Check out the following links and comparison shop the fuel injector on your Honda 1.7L Civic:
Not sure if the above fuel injectors fit your particular Civic? Don't worry, once you click on the links and arrive on the site, they'll make sure it fits! If it doesn't, they'll find you the right one.
Checking The Injector's Internal Resistance
To find out if the fuel injector's internal coil has a short or an open in its coil windings, the first thing we'll do is check its internal resistance.
Unfortunately, the Honda manual doesn't list a specific resistance specification for the fuel injectors (for the 1.7L Civic engine). We can still test them, but it'll require testing all 4 fuel injectors and then making sure that all 4 resistance values are similar.
Any fuel injector resistance that is radically different from the majority points to a fuel injector that has an open or a short in its internal coil winding.
It sounds complicated, but it isn't. This is a very easy test that can be accomplished with a simple multimeter. The multimeter will set to its Ohms (Ω) mode to check the injector's resistance.
NOTE: Don't have a multimeter or need to upgrade yours? Check out my recommendation: Buying A Digital Multimeter For Automotive Diagnostic Testing (found at: easyautodiagnostics.com).
Alright, here are the steps:
- 1
Disconnect the fuel injectors from their harness connectors.
You'll need to remove the air cleaner assembly to get to the fuel injectors. - 2
Set your multimeter to Ohms (Ω) mode and:
measure the resistance of the fuel injector across its two male spade terminals with the multimeter test leads (see the illustration in the image viewer). - 3
Write down the resistance value that your multimeter records for the specific fuel injector you're testing.
- 4
Repeat steps 1 through 3 on the remaining fuel injectors.
Let's find out what your specific multimeter Test results mean:
CASE 1: All fuel injectors registered the same resistance values. This confirms that the fuel injector your are testing is OK.
Here's why: If any one of the fuel injectors were bad, your multimeter would've registered a completely and totally different resistance value (for that fuel injector). Since your resistance (Ohms) Value were the same for all, this is an indication that the fuel injectors do not have an internal electrical fault.
CASE 2: One of the fuel injectors registered a completely different resistance value. This indicates that the fuel injector is bad. Replace the fuel injector.
