Something off-roaders might not always think about is their fuel injectors. Tucked away in the engine and invisible unless purposely removed, their status is all but unknown unless an engine rebuild is underway. Even if they’re removed, cleaning them requires special techniques and tools – something that can’t be found just by browsing the Sears catalog.
Fortunately, here in Southern California, RC Fuel Injection is one place to go when it comes to injectors. The company is a major hub of all things injector-related, and one of its most vital capabilities is its injector cleaning service, available to all who need it (and not just off-roaders).
The various types of injectors that can be worked on at RC Fuel Injection.
*Pictures with SinglePatterntest are testing a single injector at a time. This is more ideal for seeing the debris coming out. It’s also the first injector cleaning machine that Russ, the founder, ever built. The meter on the side shows how much flow is going through it. It can go from 1-100% duty cycles. It can go to 999,000 rpms. Certiflow4 means 4 tubes, each with 1600cc per minute flow rate. Certiflow8 is a whole different machine, can test up to 8 injectors at a time, and test different banks like it does in picture ending “550-1.” 550 means 550cc flow rate.
We spoke with RC’s Keoki San Miguel to get a better sense of what the service entails and what might constitute a need for it. “One of the things we do here is our injector cleaning service,” he said. “We’ve seen plenty of off-roaders, especially guys with sand rails, bring in injectors that need cleaning. The kind of driving they do – aggressive, out in the open – makes the injectors more prone to clogging and wear and tear.”
A set of injectors for an Acura Integra. This photo was taken prior to the cleaning service.
From bad fuel to loose sand or dirt, injectors don’t respond well to getting contaminated. Also, harsher fuels like E85 or 110 octane have a way of eating away at the injectors. “They’re a little bit more corrosive,” said San Miguel.
So how does RC Fuel Injection take care of injectors that come in for cleaning? According to the website, a special, custom-designed and computer-controlled flow-testing machine is used. The injectors are installed into the machine, and are then pumped with a predetermined volume of test fluid. “The test fluid is non-flammable but has a similar consistency to gasoline,” said San Miguel. “It’s safe to use, since gasoline would be more dangerous.”
One of the machines that can be used in the cleaning process is this Certiflow 4. It has a 1600cc per minute flow rate.
This large contraption is a single tester, and was the first machine ever built by RC Fuel Injection's founder, Russ Collins.
The test fluid is pumped at a precise pressure, while simultaneously, the injectors are pulsed by drivers, and the machine measures how long it takes for the test fluid to pass all the way through. From this measurement, the machine determines what the flow rate is. Technicians also observe the injectors during this whole process, watching for any signs of poor spray patterns.
After this is finished, the injectors are taken to an ultrasonic cleaning machine. “This process is similar to what a dentist would use,” said San Miguel. “It helps break up the loose dirt and debris that’s in the injectors. Oftentimes, I’ve seen how much dirt can come out of these things, just from constant use.”
The ultrasonic phase places injectors in a bath of cleaning fluid, while the injectors are connected to a power supply and are pulsed for about an hour. Simultaneously, sound waves help to break off debris from the injectors.
The last step of the process is to take the injectors back to the flow-testing machine, where they are run once again. From this, a report is printed. The report lists fuel flow rates for before and after, as well as spray pattern assessments for each individual injector. The report concludes with the total fuel delivery of the set of injectors, as well as potential horsepower figure based on fuel consumption rates.
In all, this service sounds like a great way to find out not just the status of a given set of fuel injectors, but also their potential to deal with power adders – nitrous oxide, turbochargers, and superchargers. We recommend you check out RC Fuel Injection’s website for more information.
The refreshed and rejuvenated injectors (left) have been bead-blasted and lacquered for protection, and all internals have been replaced, including filters, grommets, o-rings, and seals. The flow data sheet (right) is paired with the injectors, and goes over statistics including before and after flow rates, brake specific fuel consumption (BSFC), and more.