How To Test The Fuel Injectors (1999-2000 4.6L Crown Victoria)

How To Test A Bad Fuel Injector (1999-2000 4.6L Ford Crown Victoria)

If you have a multimeter, you can quickly test the fuel injectors on your 1999-2000 4.6L Crown Victoria to see if any have failed.

This multimeter resistance test isn't difficult to carry out as the injectors are very accessible. You also don't need expensive diagnostic equipment to test them (like a scan tool).

In this tutorial, I'll show you how in a step by step manner.

NOTE: The following tutorials may be of help to test the fuel injectors on the 1992-1998 Crown Victoria (Mercury Grand Marquis):

Symptoms Of A Bad Fuel Injector

Regardless of whether a fuel injector is suffering from an internal short-circuit problem or is clogged, the end result is a misfire.

You may feel this misfire when the engine is idling or under load (e.g. when accelerating from a traffic light).

Here are a few other symptoms you'll see:

  • Rough idle.
  • Lack of power.
  • Hesitation when you accelerate your car down the road.
  • Misfire trouble codes:
    • 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.
    • P0307: Cylinder #7 Misfire.
    • P0308: Cylinder #8 Misfire.

Where To Buy The Fuel Injector And Save

Do you need a new fuel injector? Check out the links below and compare injectors:

For 1999 4.6L Crown Victoria (1999 4.6L Grand Marquis):

For 2000 4.6L Crown Victoria (2000 4.6L Grand Marquis):

Not sure if the above fuel injectors fit your particular 1999, 2000 4.6L Ford Crown Victoria (Mercury Grand Marquis)? 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

How To Test A Bad Fuel Injector (1999-2000 4.6L Ford Crown Victoria)

OK, this is what you signed up for! We're gonna check the resistance of each fuel injector with a multimeter in Ohms mode.

Before you start, let me tell you that Ford made a change to its fuel injector connector. The new style of fuel injector connector locking tab has a tendency to break when simply depressed to disengage the connector from the injector

Broken fuel injector connector locking tabs are one of the most common fuel injector problems on the 1999-2000 4.6L Ford Crown Victoria. Once the locking tab is broken, the connector will make a false connection. This false connection will cause a misfire.

So before you begin to disconnect your Crown Victoria's fuel injectors, gently pull on the connector (without depressing the locking tab) to see if it will disengage from the injector.

If one of the fuel injector connectors comes loose, you have found a bad fuel injector connector that is causing a misfire. This fuel injector connector needs to be replaced.

Unfortunately, there is an 80% chance that simply disconnecting each injector for testing will break the locking tab. In my opinion this is a built in defect to force you into buying a new connector and keep the economy going.

If you need to buy the fuel injector connector, you can find it here: Where To Buy The Fuel Injector And Save.

OK, these are the test steps:

  1. 1

    Disconnect the fuel injectors from their engine wiring harness connectors.

    NOTE: Use the illustration of the engine block (in the image above) to identify the cylinder # the injector belongs to.

  2. 2

    Set your multimeter to Ohms (Ω) mode.

  3. 3

    Measure the resistance of the fuel injector across its two male spade terminals with the multimeter test leads (see the illustration above).

  4. 4

    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.

  5. 5

    Repeat steps 1 through 4 on the remaining fuel injectors.

    NOTE: The fuel injector resistance specification is: 11 to 18 Ohms.

Let's find out what your specific multimeter test results mean:

CASE 1: All 8 fuel injectors are within the specified resistance parameters (11 to 18 Ohms). This tells you that the fuel injectors are OK. To be a bit more specific, they have no internal short-circuit or open-circuit problem..

If the cylinder is misfiring, there's a good chance that the fuel injector is clogged. I suggest taking a look at the following section: How To Find The Bad Or Clogged Fuel Injector.

CASE 2: One or several fuel injectors ARE NOT within the specified resistance parameters (11 to 18 Ohms). The fuel injector whose resistance is not within the specified resistance value is defective and must be replaced.