While not considered a poor choice for preventative maintenance, on-car fuel injection cleaning is completely different from off-car fuel injection cleaning.
On-Car Cleaning Methods
First, let's cover on-car cleaning methods, of which there are two. One method simply uses a pour-in additive to the fuel tank. These additives can be found just about everywhere. The concentrated cleaner is mixed with fuel in the tank where it slowly makes its way through the fuel system, eventually passing through to the injectors.
The other on-car method uses a pressurized canister of injector cleaner. The canister is connected directly to the fuel rail. During this process, the fuel pump is disabled and the engine actually runs off of the cleaner, not the fuel in the tank. The chemical passes through the injectors, cleaning them in the process. The engine usually operates for about 5-10 minutes on the cleaner. This process is more time consuming than the pour-in method and requires special equipment and training.
So...what's the catch with on-car cleaning?
There are many disadvantages to using the on-car cleaning method. The chemicals used are not very aggressive, and they must be similar in nature to gasoline since the engine must run on the chemical alone. Because the cleaning is done on the car, the cleaner must not damage any of the other components on the vehicle that are sensitive to chemical contamination such as the oxygen sensor, catalytic converter, and others. Therefore, the cleaner used is a fairly mild detergent.
Also, the technician really never knows what results the on-car cleaning accomplished. Without being able to perform spray pattern tests, flow-rate tests, and leak-down tests, the technician “hopes” the on-car method will increase vehicle performance.
For preventative maintenance, on-car cleaning usually won't hurt. However, if an injector is restricted to the point that it is causing a drivability problem, don't expect on-car cleaning to help. At this point, you're most likely wasting time and money.
Off-car cleaning methods
Off-car cleaning is a completely different process than either method used for on-car cleaning. GB Remanufacturing's 15 step cleaning and testing process assures the customer that their injectors are performing to original OEM specifications.
Using ultrasonic technology, the injectors are cleaned internally and externally while being pulsed at varying pulse widths and frequencies (RPM). The ultrasonic waves create cavitation bubbles in the cleaning fluid. When the microscopic bubbles touch a surface, they implode, creating forces in excess of 10,000 psi. These implosions, combined with the correct cleaning chemistry and the all important “reverse or back-flush” are what guarantee a thoroughly cleaned fuel injector.
GB's R&R service includes this and a whole lot more. After the injectors are ultrasonically cleaned they are flow tested to ensure they are within manufacturer's specifications. They are leak tested, all internal filters are replaced, o-rings are replaced and the injector's electrical coil is fully tested.
For more information on GB's R&R service contact us toll-free at (866) 4GB-REMAN.
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