The side feed fuel system in your Nissan 240SX can cause misfire when your 240SX Fuel Injector goes bad. Although there can be other issues to your ignition misfire in your 240SX, the fuel injector is a common Nissan issue. Today I’ll be showing you how to test the 240SX fuel injector in a 1995 Zenki.
In order to test your 240SX fuel injector, you will need to use a digital multimeter. You’ll be using this multimeter to determine whether or not your 240SX fuel injector is clogged or not. By measuring the pins on your side feed fuel injector, you’ll be able to see if the internal windings have gone bad or not.
Whether or not your Nissan 240SX fuel injector has clogged or failed internally, it will cause your 2.4 liter KA24DE engine to run rough. Your KA24 engine will also have a rough idle, and poor engine performance.
Of course one of the first signs of trouble you will notice in your OBDII Nissan is the 240SX check engine light. If the CEL turns on while you are driving, you’ll need the right OBDII scan tool to check what the code is.
These stored Diagnostic Trouble codes can tell you which cylinder is having an issue. That will eliminate quite a bit of guessing when you want to find which 240SX fuel injector has gone bad.
Although I’ll be showing you how to test the 240SX fuel injector in a 1995-1998 Nissan S14, this test can also be applied to the S13. Because your 2.4 liter KA24 engine uses a side feed setup, it’s rather easy to test it once you have the hood open.
The side feed injector clips are easily found along the passenger side of the engine mounted near the intake manifold. You can easily unplug each of the 240SX fuel injector connectors by depressing the plastic pin.
If it makes the job easier you can also undo the front distributor and cam angle sensor harness as well. This will allow you to flip the engine harness up and out.
Once you’ve got each one of your 240SX fuel injector clips undone, you can test the resistance. If your OBDII trouble code tells you which cylinder is misfiring, this makes this part of the test easy.
However if you have a generic engine misfire code, it’s best to test all of the injectors. Test each one and record your findings to discover which injector is the problem.
Test your 240SX fuel injector resistance
Refer to the 240SX fuel injector wiring diagram below to test the internal windings. Testing the 240SX fuel injector is easy using your digital multimeter.
Turn the dial of your multimeter to read resistance or OHMS.
Gently probe the two pins of your 240SX fuel injector.
You should see a value of internal resistance here. This number should fall between 9 and 14 OHMs Ω. Remember that this is for the 1995-1998 Nissan 240SX.
If you happen to own a S13, this value is slightly changed. The value for the internal resistance of your S13 240SX fuel injector should read between 8 and 12 OHMs Ω.
When you find any of your fuel injectors don’t respond the right way, you’ll need to remove the unit and replace it. If your 240SX misfire issues still continue after replacing your faulty 240SX fuel injector, you can also check your ignition distributor.
There’s also a small chance that your engine harness or ECU is at fault as well. This can be a huge problem especially if each one of your 240SX fuel injector checks out okay. To test this use an automotive noid light to check and make sure that each KA fuel injector wiring connector is lighting off properly.