How To Test a Ford Mustang Fuel Injector

February 1, 2016

The primary role of your Mustang fuel injector is to deliver the right amount of fuel to your combustion chamber. This injector relies on your engine computer to trigger or activate. The Mustang fuel injector also depends on your fuel filter to provide clean fuel that’s free of particulates or debris. Over time however your fuel filter may break down or not do it’s job, which could cause your Ford injector to clog.

When this occurs it’s pretty obvious that your Mustang isn’t running quite right. When the injector clogs or even outright fails it’s going to cause an imbalance in your 4.6 liter engine. Today I will be showing you how to test your Mustang fuel injector by using a multimeter. This test will show you whether or not the injector has clogged or if the internal windings in it have failed.

I’m going to be showing you how to test this in a 2001 Ford Mustang Cobra. This engine is the same 4.6 liter V8 engine that’s one of the most common Mustang engines of all time. This testing procedure is the same for any year Ford GT or Cobra from 1996 to 2005.

So chances are your Ford V8 is not running so great. You might have a check engine light on or it may sound like your Mustang is missing or it’s idling funny.

But you aren’t sure whether or not you need a replacement fuel injector or just to have the unit cleaned. This how to DIY guide will help you identify what the issue is in your Ford Mustang GT.

If your check engine light is triggered on by your On Board Diagnostics, you’ll need a scan tool to pull the code and clear it. If you already know how to use a digital multimeter, you are ready to get to testing.

If you are unsure of what this kind of tool this is, you can learn all about them here. The replacement Ford Mustang fuel injector carries quite a few different part numbers. Ford OEM part numbers are below :

F0TZ9F593DA
F0TZ9F593C

Aftermarket multi port fuel injectors for your 4.6 liter Ford Mustang can range in part numbers. Here’s a few of the common part numbers at the bottom of this guide for you to reference.

Problems with your Mustang injectors can be easy to test using your digital multimeter, especially if they are on the driver side. In the event that your injectors need testing on the passenger side of your 4.6 liter engine, you will need to remove the top half of your intake manifold.

Removing the top portion of your intake manifold is easy to do. You will need to disconnect your Mustang MAF or mass air flow sensor however.

Taking off your Mustang mass air flow sensor is simple. If you have ever upgraded your MAF sensor or installed an aftermarket intake kit, chances are this is the easiest part of this DIY guide.

Now that you have access to your fuel injectors disconnect the problem unit. If you want to know whether your Ford Mustang fuel injector has clogged or just plain gone out, you’ll need to measure the internal resistance.

Measuring the Mustang fuel injector resistance

Your factory fuel injector uses two pins to operate. Take your multimeter and turn it to the read resistance or the OHMS mode. Now you will be gently probing the fuel injector itself, to make sure that the internal windings are still intact.

The internal resistance of your 4.6 liter fuel injector will tell you if it’s gone bad or it’s just clogged. Measuring the resistance between these two pins should reveal an internal measurement between 12 and 18 Ohms Ω.

It’s a good idea to test all of your injectors just to ensure that they are within this operating range. While the measurements may vary from injector, just remember that the measurements should fall between this range.

When testing all of your injectors make sure to record your findings. If any of your injectors do not measure within this specified range, the Mustang fuel injector has failed. If your injector does check out but you are sure that cylinder is having an issue or no fuel is being delivered, the Mustang fuel injector has clogged.

Taking your Mustang fuel injector in for service gets it cleaned and balanced properly. If not you will need a replacement fuel injector. If you are shopping for a replacement Ford Mustang fuel injector, there’s also several aftermarket units to choose from. Some of these part numbers include :