What does an injector leak off test do?
Injectors can leak in two different ways. The Leak-Off Test above is measuring the leakage through the valve. Excessive leakage makes it impossible for the injection pump to achieve or maintain the pressure in the common rail that the ECU demands.
How does a leak off test work?
An engine leakdown test is a compression test in reverse. Instead of measuring the engine’s ability to create pressure, compressed air is introduced into the cylinder through the spark plug hole. The loss percentage will indicate the condition of the cylinder and overall condition of the engine.
How do I know if my diesel injector is leaking?
Symptoms of Leaking Fuel Injectors:
- Hard Starting when engine is hot.
- Increased Fuel Consumption.
- Rough Idle.
- Fuel odors inside and around the car.
- Poor Emissions.
- Oil thinning, which can lead to catastrophic engine failure.
- Hydro-lock, which can lead to catastrophic engine failure.
How do you tell if an injector has gone?
The most common sign of a bad fuel injector is the check engine warning light, which appears on the dashboard. As soon as an injector isn’t doing what it should, this light will come on. (In other words, if it’s adding too much or too little.)
What causes injector leak back?
Another common fault by contamination or wear and tear over time is that the pilot valve within the common rail injector gets worn which causes your injector to back-leak which causes your vehicle to stall, run rough, have lack of power and eventually not run.
What happens when an injector fails?
A faulty fuel injector may cause a rough engine idle if it fails to deliver a steady, constant stream of flow to a vehicle’s engine. A dysfunctional fuel injector may inject too much or too little fuel into an engine’s cylinders. Both scenarios can cause a rough engine idle.
How does the leak off test work on an injector?
Injectors can leak in two different ways. The Leak-Off Test above is measuring the leakage through the valve. Excessive leakage makes it impossible for the injection pump to achieve or maintain the pressure in the common rail that the ECU demands.
Can a fuel injector be tested under pressure?
Fuel injector leak testing should be done under operating pressure. The average DIY fuel injector cleaning project and most automotive repair shops does not have the proper diagnostic equipment or the ability to test leaking injectors or clean them properly.
How can I check if my injector has been cut?
To confirm a suspect pulsation (and so an injector), you can introduce a misfire with a Cylinder Cut feature in a scan tool, or substitute an injector with a load box. This will remove the back-leakage contribution for the injector that has been cut and confirm if it is the offending injector.
What happens if you don’t plug in the injector?
If you don’t plug these pipes then air will be drawn into the high pressure injection pump which will cause problems with running the engine for the test. Then plug your connectors onto the injectors. The hair colouring bottles come with tapered nozzles that you can cut the end off and push the clear plastic tubing onto them.