How to Ensure Fuel Injector Is Receiving the Correct Voltage?

Fuel injections are responsible for passing the right amount of fuel into the cylinders. Since these fuel injectors work millions of times, they may wear off. Bad fuel injector doesn’t maintain the fuel consistency in the right amount, and that affects overall fuel economy plus poor engine performance.

Hence one should always check if fuel injectors are receiving the correct voltage or not.

Testing Fuel Injector for the Correct Voltage

First, we would start with testing the injector resistance, and then we would check them for the wiring.

You would need a Digital Volt-Ohmmeter (DVOM) or multimeter with ohms setting.

Make sure the engine is off since you don’t need power for this checking. You can access the injectors in the engine or use the manual. There may be a plastic shield that you need to remove to access injectors.

Remove injector wiring harness; if there is a slide lock then you need to remove it first to access the wiring harness.

Fuel Injector
Fuel consistency is determined by car fuel injectors. Source: Amazon


Now you need the DVOM set to measure ohms. Check all the injectors one by one for their resistance. If the meter doesn’t auto range, set it to the lowest range.

If you have high impedance injectors that are common in cars these days, then the range would be from 12 to 17 ohms.

Low impedance injectors would display you a range from 2 to 5 ohms. You need to repeat this action with all the injectors, and each one of them should have almost similar resistance to each other.

If you find any injector to have a major difference in the resistance, it means that injector needs to be inspected. If you want to find the exact resistance for the injectors, you can search for your vehicle’s repair guide.

The Second Part

In part two, we would test the injector wiring to make sure if everything is connected properly.

In this test, you need to keep the key to the second position that is ON. This way you would receive the battery power without turning on the engine.

Now you need the DVOM to measure DC voltage, and same as prior, if the meter doesn’t auto range, set it to the lowest.

Take the negative lead of the DVOM and touch it to a ground source. You can look for an unpainted piece of the frame that you can find under the hood. Protect your car against every odd by having these maintenance tips by your side.

Take the positive lead of the meter and connect it to the wiring harness terminal.

Upon doing this, one terminal should read 0 volts and the other one as 12 volts or around 12.

While leaving the ground lead in position, you need to test the wiring harness of all the injectors. If the reading is around 12 volts for each injector, then everything is fine. But if the reading is too low, it means there is a problem in the wiring.

Fuel Injector
Major difference between injectors reading is bad sign. Source: Hotcars


If you find an issue either in the first part or second, you should take your car to a professional repairer. You would be saving huge bucks by getting the fuel injector right that otherwise would be spent on the fuel.