Many drivers forget about the hard working, fuel squirting Injectors that are a vital part of the engine. Sooner or later the fuel injectors will get dirty and clogged, causing the vehicle to show signs of less efficient drive-ability. This is not a case of if, it's a case of when. It's just one of those unavoidable things that comes with the territory of driving modern day, fuel injected engines. Even though we cannot be absolutely sure there is a problem with the injector without physically removing them, there are some clogged fuel injector symptoms that we can notice.
Engine stutter or hesitation: without the proper air/fuel mixture, the combustion inside the chamber is hindered.
Performance Loss: If combustion is hindered, engine power suffers.
Increase Fuel Consumption: when fuel combustion efficiency is negatively affected, you will often burn more fuel to achieve the performance needed.
Engine Misfire: poor air/fuel mixture in the cylinders can cause incomplete combustion.
Rough idling/engine stalling: uneven supply of fuel during idling can cause RPM to fall too low and result in stalling.
Emissions Test Fail
There are many reasons to have a vehicles fuel injectors cleaned. The main circumstances include fuel contamination, having uneven cylinder fueling/spark plug wear, an unexplained cylinder misfire where you have spark, general maintenance 80k-100k miles, and for peace of mind at time of engine rebuild.
Fuel injector cleaning methods and results vary dramatically whether you choose to perform an on-car cleaning method, or an off-car fuel injector service.
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. 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.
There are many disadvantages to using the on-car cleaning method. The chemicals used are not very aggressive. The chemicals used have to 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 test, 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 driveability problem, don’t expect on-car cleaning to help. At this point, you’re most likely wasting time and money.
Off-car cleaning is a completely different process than either method used for on-car cleaning. Once the injectors are removed from the vehicle they are cleaned ultrasonically. 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 “back-flush” are what guarantee a thoroughly cleaned fuel injector.
Once the injectors are cleaned, their operation is verified using the injector flow bench. The flow bench can be used to examine the injector’s spray pattern, dynamic and static flow rate and to perform a leak test, none of which can be performed with the “on-car” method.
Once the injectors are cleaned and fully tested, critical components are replaced to complete the service. This includes any o-rings, seals, filters and pintle caps.
When we are done the injectors are as good as or better than rebuilt injectors that can be purchased at any auto parts store.
The Dyno Shop in Santee, CA is here to help you with any of your vehicle needs!!!