Testing the fuel injectors on the 2.5L V6 Chrysler/Dodge engine can be quite a challenge since 3 of the 6 fuel injectors are underneath the intake manifold plenum.
This means that if you suspect that you've got a bad fuel injector (causing a misfire/rough idle condition) you'll need a specific diagnostic strategy. In this tutorial will explain what's involved in testing them and if you don't know where to start, I've got a couple suggestions for you.
Contents of this tutorial:
NOTE: This tutorial applies only to the indicated 2.5L V6 equipped vehicles listed in the Applies To: box on the right column (or at the bottom of the page).
You can find this tutorial in Spanish here: Cómo Probar Los Inyectores De Combustible (2.5L V6 Chrysler) (at: autotecnico-online.com).
Symptoms Of A Bad Fuel Injector
As you're already aware, each of the engine's 6 cylinders needs 3 specific things to produce power. These 3 are: air, fuel, and spark. If any one of these are missing from any one cylinder... that cylinder is gonna' misfire.
So, a fuel injector that's not injecting fuel will cause a misfire condition on your 2.5L V6 equipped Chrysler/Dodge vehicle.
Now, a misfire condition is not the only symptom that your vehicle may experience. Here are some more specific symptoms:
- Rough idle.
- Lack of power.
- Hesitation when you accelerate your 2.5L V6 equipped Dodge (Chrysler) down the road.
- Since your vehicle is OBD II equipped, you'll see a misfire diagnostic trouble code (DTC):
- P0300: Random Cylinder Misfire.
- P0301: Cylinder #1 Misfire.
- P0302: Cylinder #2 Misfire.
- P0303: Cylinder #3 Misfire.
- P0304: Cylinder #4 Misfire.
- P0305: Cylinder #5 Misfire.
- P0306: Cylinder #6 Misfire.
The fuel injectors, on your 2.5L V6 equipped Chrysler/Dodge can fail in one of several ways:
- The fuel injector shorts out or becomes ‘open’ internally. When this happens, fuel injector stops injecting fuel.
- The fuel injector becomes clogged and doesn't atomize the fuel correctly.
- It comes on and does not turn off (due to electrical issues). In other words: it does not pulse on and off but stays on all of the time spraying a tremendous amount of fuel as soon as you turn the ignition key to the ON position.
Whether the fuel injector is fried internally or clogged, this tutorial will offer you some specific suggestions to help you narrow down the possible solution.
Checking The Injector's Internal Resistance
Before you start, have you already eliminated the ignition system and engine compression as the cause of the misfire condition? If you haven't already, take a look at the following section: How To Find The BAD Or Clogged Fuel Injector.
OK, as you're already aware, the upper intake manifold plenum has to be removed to access the fuel injectors for cylinders #1, #3, and #5. I don't include any R & R (remove and replace) info but I do have a few suggestions for you before you start here: Precautions When Removing the Upper Intake Plenum.
NOTE: Don't have a multimeter or need to upgrade yours? Check out my recommendation: Buying A Digital Multimeter For Automotive Diagnostic Testing.
Alright, here are the steps:
Disconnect the fuel injectors from their harness connectors.
NOTE: The illustration above will help you identify the cylinder # the fuel injector belongs to.
Place your multimeter in 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).
Write down the resistance value that your multimeter records for the specific fuel injector you're testing. The illustration above will help you identify the cylinder # the fuel injector belongs to.
Repeat steps 1 through 3 on the remaining fuel injectors.
NOTE: The 2.5L V6 fuel injector factory manual resistance specification is approximately: 8.5 to 15.5 Ohms.
Let's find out what your specific multimeter test results mean:
CASE 1: Your multimeter reports all fuel injector resistances are within specification. This tells you that the fuel injectors are OK on your 2.5L V6 Stratus (Cirrus, Sebring, or Avenger). Specifically, that none are shorted or open internally.
Here's why: If any one of the fuel injectors were shorted or open internally, the fuel injector would have registered a radically different resistance value on your multimeter. Since the resistance values for all 6 were uniform, this test result tells you that they are not defective.
CASE 2: Your multimeter reports a fuel injector with a completely different resistance value. This indicates that the fuel injector is BAD. Replace the fuel injector.