How To Test Your Nissan Altima Fuel Injectors

How To Test Your Nissan Altima Fuel Injectors


Youv’e got four fuel injectors in your Nissan Altima, and when the seals and internal components of your injector begin to fail, your Altima can suffer. Leaking or problematic Nissan fuel injectors can cause many OBDII trouble codes, many of which could sideline your Altima and make it non-driveable. Today we’ll be showing you how to test your Nissan Altima fuel injectors in a 2006 with the 2.5 liter QR25DE engine in it.

The part number for these Nissan Altima fuel injectors is 16600-8J010, and there’s a few interchange part numbers that match this part. When learning how to test your Nissan Altima fuel injectors, all you need is a 10mm wrench and a multimeter. Not sure what a multimeter is or how to use one? Check out our handy voltmeter / multimeter guide here.


As I stated previously, problems with your fuel injectors can lead to a bunch of different problems. The problem is, many of these OBDII trouble codes can often be misdiagnosed as another problem, which can waste valuable time and money. Here’s just a few OBDII trouble codes that learning how to test your Nissan Altima fuel injectors can fix.

  • P0300: Random Cylinder Misfire
  • P0301: Cylinder #1 Misfire
  • P0302: Cylinder #2 Misfire
  • P0303: Cylinder #3 Misfire
  • P0304: Cylinder #4 Misfire

Learn how to troubleshoot ignition misfire using our handy guide on Nissan misfire, and when you’re ready let’s continue our guide on testing your Altima injectors.


Fuel trim lean or rich trouble codes can also arise from a faulty fuel injector, if you are having problems with your Altima and need guidance on how to troubleshoot your issue, head over to DTC Doctor.

Before beginning our how to test your Nissan Altima fuel injectors, open your hood. Using your 10mm wrench, carefully remove the nuts that hold your Altima engine cover in place. Remove the engine cover and set to the side, you should now see your bare engine in front of you.


Your Nissan Altima fuel injectors are like any other injector in that there’s an internal resistance that’s vital to the normal day to day operation of your QR25DE engine. In order to determine this, you’ll be using your multimeter to measure the fuel injector to see if it’s failed.

Once you’ve got the QR engine cover removed, you can see your Nissan Altima intake manifold and fuel rail along with your injectors. Carefully unplug your fuel injector clips, and leave the fuel injectors unplugged. Get a piece of paper ready, as you’ll be recording your findings as you test each fuel injector.

With your multimeter in OHMs mode, connect the two leads to the fuel injector terminals. Begin with cylinder #1, which is located on the passenger side of the engine. Nissan calls for a resistance range between 12.1 and 12.9 Ω for each fuel injector in your Nissan Altima. Measure and record your findings for cylinder #1, and move down the line as you test all four injectors.

If you find one of the injectors internal resistance is out of range, or even showing as open, it’s dead. Replace the unit with the part number above and fix your Nissan Altima the fast and easy way.

However, if you find that all four injectors have a good reading this complicates matters. If you have a stored OBDII DTC, check this against your findings to discover any other possible causes. If your condition is a misfire, make sure to check your ignition components, starting with your spark plugs, your coils and igniter.

How To Test your Nissan Altima


If you are still having problems locating your dead cylinder, there’s an easy way to test your Nissan Altima. Leave your engine cover removed and then start your engine. Stay away from the accessory belts as well as your cooling fans during this part of our test.

Carefully unplug one fuel injector at a time, what you are looking for is the cylinder that doesn’t change your idle too much or at all. When you disconnect a good fuel injector and good QR25DE cylinder, the engine should stumble and try to die.

If you are unplugging a fuel injector for a particular cylinder, and the engine does not change much, this is probably your culprit. Perform a leakdown or compression test in order to determine what the problem is.

That does it for our how to test your Nissan Altima fuel injectors DIY Guide, if you have any questions about our guide, leave them below!