We do off-car fuel injector flow testing and ultrasonic cleaning in our Berkeley, CA shop. We only offer this service as a full-service option. In other words, you can’t bring your injectors to us to have them cleaned, but you can bring your car if you think it has an injector issue. We will diagnose your car and, if needed, remove the injectors, flow test, clean, then flow test again. Also, we only service Toyota, Honda, Subaru, and Mazda.
If you’re looking for a mail in option, you could try Doctor Injector in Rancho Cordoba.
Should You Get Your Fuel Injectors Cleaned?
Fuel injector cleaning is a controversial topic. There are two main reasons for this. First, most Japanese manufacturers don’t recommend cleaning; they recommend replacing the injectors when they aren’t working properly. The other reason for the controversy is that most methods of cleaning fuel injectors don’t do anything other than generate profit for the shop performing the service.
Why Some Methods of Fuel Injector Cleaning Won’t Work
“Fuel injector cleaning” can range from dumping a can of cleaner in the fuel tank, to connecting a machine to the car’s fuel rail to run concentrated cleaner through the injectors, to removing the injectors, flow testing, ultrasonic cleaning, then rechecking flow.
In my experience, if the car has an actual problem, such as an intermittent misfire due to poor flow or a poor spray pattern, adding injector cleaner to the tank or using a machine that add pressurized cleaner to the rail will do nothing to correct the issue. Also, the solvents used in rail cleaning systems can damage the catalytic converter. On-car cleaning isn’t a good option in our opinion.
I suppose there’s the possibility that regular cleaning with either of these two on-car methods might prevent a problem from developing. But as a guy who was selling a tool to “fix” bad hybrid batteries once told me, “This tool works much better on cars that don’t have a problem”. Do you know what else works well on cars that don’t have a problem? Doing nothing. There’s a line between preventative maintenance and “wallet flushing”. Almost all mechanics agree it exists, we just can’t agree on where it lies.
Why Fuel Rail Cleaning Is A Bad Option
The cost of using a fuel rail type machine periodically would quickly equal the cost of just waiting for the injectors to clog and then replacing them, so there’s not really any value to using a rail type machine as preventative maintenance. As far as adding injector cleaner to the fuel tank, virtually all gasoline already has cleaning agents to remove carbon from intake valves and injectors. I don’t think adding more cleaner will do much. However, if you want to add a bottle of Chevron Techron or similar every 40 or 50 tanks, it won’t hurt anything and it may do some good.
So if the in-tank and rail systems don’t work, what does? Ultrasonic cleaning works almost all the time. Ultrasonic cleaning requires removing the injectors from the car. On some cars this isn’t that much work, but on others it’s quite a project.
What is Ultrasonic Fuel Injector Cleaning?
An ultrasonic cleaner is a device that uses high-frequency sound waves transmitted through a liquid in a tank to create microscopic bubbles (cavitation) that effectively remove contaminants from submerged objects. There are a couple things that make an automotive injector cleaner a little different.
- The liquid in the tank is a special solvent that works especially well to remove carbon an varnish deposits
- There are electrical controls that cycle the injector on and off (open and closed) so that the inside of the injector is cleaned
Flow Testing Injectors – A Critical Step
Since injectors can be difficult to remove and replace on some cars, and ultrasonic cleaning doesn’t work 100% of the time, testing is a key part of the process. Before cleaning the injector, we flow test it at a variety of pulse widths and frequencies to simulate its operation on the car.
There’s no way to test the flow rate against manufacturer’s specifications for a couple of reasons. First, the specification isn’t published in a service manual. Why would we need to know, right? We’re not supposed to be cleaning them! Second, injector flow testing is typically done with a calibration fluid that will closely match the characteristics of gasoline without the flammability. Without knowing the test conditions, fluid, and specifications, we can’t test just one injector.
Luckily cars have multiple injectors, and they’re all exactly the same. We test before and after fuel injector cleaning to make sure it worked. If we flow test four injectors and they all flow different amounts of fuel, one or all of them is/are bad. If after cleaning they all flow the same amount, then the cleaning was successful.
Fuel injectors usually cost somewhere between $100 and $200 each. On a 6 cylinder car our customers can save a lot of money with cleaning vs. replacing.
How often should you clean injectors?
As I mentioned earlier, if you’d like to add some injector cleaner to your fuel tank periodically, there’s nothing wrong with that and it may do some good. However, there’s no reason to remove and clean fuel injectors unless there’s a problem. It’s not something that should be performed periodically.
Why Would You Clean Fuel Injectors? / What Are The Symptoms of Clogged Injectors?
If one or two injectors start to clog you’ll likely notice a misfire, or at least your car will, and the check engine light will come on. If all of the injectors are flowing less that normal you’ll probably get a check engine light and a P0171 trouble code indicating that the ECM is needing to add more fuel that what’s in the default fuel map.