How to test a fuel injector with a battery

To properly do this test you have to ensure you leave the fuel lines on the fuel rail to deliver adequate fuel pressure from the fuel pump. Set the ohms meter to 12 volt use a 12 vote or a 9 vote battery side to meter - side to the injector from the injctor to the meter.

If you want to test the injector signal use a scope.

How to test a fuel injector with a battery. You can check fuel injectors with a 9V volt car battery or with a 12 V car battery. Some engines of vehicles have plastic panels those need to be removed before you can come across the fuel injectors. They are usually secured by bolts and are removed with the help of a.

Testing fuel injectors with a 9v battery - YouTube. Easy way to check for a bad fuel injector using some wire and a 9v battery. This will work on most cars.

Set the ohms meter to 12 volt use a 12 vote or a 9 vote battery side to meter - side to the injector from the injctor to the meter. If you see 12 volt on t. Petrol fuel injector test function pulse testing injectors using a 12 volt car battery - YouTube.

Petrol fuel injector test function pulse testing injectors using a 12 volt car battery. Here I show how I tested my fuel injectors with a 9v battery. I was looking to see if any of the injectors were clogged or if they had a bad spray pattern4.

Check the power side of the circuit for a short blown fuse or bad connection along the circuit including the computer. Now plug back the harness connector to the fuel injector and hook the test light clip to the positive side of the battery. Have an assistant crank or start the engine.

Now connect the fuel injector to the harness connector and plug the test light clip to the positive side of the battery Let an assistant to start or crank the engine Inspect the opposite wire on the fuel injector connector again this is the pulse signal that comes from the computer. Unplug the injector in question and insert the positive voltmeter lead into one of the two connector slots coming from the injector wiring harness. Touch the other lead to the engine metal — not plastic — for a ground.

Have an assistant turn the key on. If there is no voltage test the second connector slot. This type of injector circuit is called negative trigger.

There are however a few European manufacturers that have used positive or battery voltage trigger injector circuitry in the past. With positive injector trigger the positive side is the one being triggered by the ECM. Valve testing can be done with the injector still installed using a fuel pressure gauge while hot wiring the fuel pump to stay on.

Carefully attach a 12 volt power power and ground source to the injector you should be able to see the gauge fluctuate as you connect and disconnect the circuit if the injector valve is working and not plugged. VS211 tests for clogged or leaking fuel injectors by using a single half-second pulse. Multiple 5-millisecond pulses are used to test for sticky or sluggish fuel injectors.

By using a fuel pressure gauge VS210 optional and comparing fuel pressure differences VS211 FUEL INJECTOR HARNESS TESTER. A A Noid light available from Autozone is one way to test the injector wiring. If the light stays on constantly either the wiring has a short to ground or the computer has failed B I like to use an old injector with compressed air applied to the injector where the fuel rail would normally connect.

If you want to test the injector signal use a scope. As you identified one side is 12V the other side gets connected to ground by the Motronic ECU pin 14 and 15. It looks like they apply a peak-and-hold signal.

Id like to do a volume test on my injectors and was thinking that I would activate each one by jumpering it to the battery about 15 seconds per injector. The thing is that if I understand correctly most injectors run on 5 volts as they are controlled by the ECU and was wondering if activating them like this for short times with the 12 volts from the battery is safe in general and safe for the injectors. Put on a mechanics stethoscope and probe the suspected fuel injector by placing the tip of the tool against the injectors body.

You should hear a series of clicks as the injectors valve opens and closes. If you do not hear the clicks the injector is bad or not receiving power. Turn off the engine.

Unbolt the fuel rail and gently pull off the rail with injector remover. To properly do this test you have to ensure you leave the fuel lines on the fuel rail to deliver adequate fuel pressure from the fuel pump. Get something to measure the fuels pressure something like a syringe that has milliliters.

Remove the negative battery cable from the battery. Depressurize the fuel rail if you have pressurized it for the residual pressure test. Disconnect the fuel injector wires from the fuel injector heads by unsnapping the clips.

Use a fuel line wrench to loosen the fuel rail inlet line. Use a socket extension and wrench to loosen the. Following points to be remembered while testing of fuel injector.

Visually examine the injector just after taken from cylinder head. Pressure test and find opening pressure in service. Check injector setting pressure formation of trumpets and carbon accumulation corrosion at the nozzle etc.

Spray pattern assessment and prompt re-seating. Battery voltage does work and is what this system was designed for. If you look at the Engine Management picture from the manual I posted it shows the power to the injectors is from the battery through the DME relay and the manual states you should read battery voltage when testing the injector.