For this check, you do not need the vehicle running or the ignition to be on. You will be checking Ohms. Most fuel injectors will have an electrical resistance of 10 to 18 Ohms

First, remove the corresponding electrical connector from the injector you wish to test.

Now you should see two metal prongs (contacts) inside where the connector was. Set your meter to the Ohms setting.

Next touch your red meter lead to one injector contact, and the black meter lead to the other contact. Since you are in the Ohms setting, it does not matter which lead goes on either contact. With the meter in the lower Ohms setting, you should get around the same resistance on all your injectors.

If one injector is reading much higher or lower than the rest, it is most likely bad. If you get an open (O.L.) or zero Ohms (shorted), then your injector should be replaced.

You could also check a fuel injector by carefully putting a long screwdriver directly on the injector while the engine is running.

Using a long shank screwdriver, hold the screwdriver handle up to your ear, the shank on the sensor itself, and you should be able to hear a clicking noise. If not, then it is probably either clogged or the circuit inside is open.