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PRACTICAL : 6 PERFORM SERVICE AND TESTING OF INJECTORS

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PRACTICAL : 6 PERFORM SERVICE AND TESTING OF INJECTORS Who needs injector service? There are several reasons why injector service may be necessary: Decreased Performance A decrease in fuel economy in any car is a telltale sign of an injector problem. Likewise, once any car has reached 75,000 miles, fuel economy and performance decrease as well… Injector service is required. Get your injectors cleaned and tested and regain the gas mileage, decreased emissions, smooth operation and performance you used to have. The Unknown Injectors that have been sitting outside of the car for an extended period of time or injectors purchased without a known history can be problematic. Are they clogged? Do they have any electrical problems? Does the set flow evenly? Injector Service will insure cleanliness, test for all issues and provide a valuable flow report. Tuning When new injectors are installed, especially if they are a different size than stock and/or if other engine modifications are made at the same time, the car’s ECU cannot properly regulate the injectors – Tuning is required. DeatschWerks Advanced Injector Testing provides the data necessary to optimize the idle, drivability and power you require from your new injectors.

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Fuel Injector Servicing An engine will not perform at its best without the proper air/fuel mixture. The fuel system of a modern computer-controlled fuel injected engine is so reliable that it seems to be almost maintenance free, but these modern fuel injected engines have fuel injectors that become flow restricted or “dirty” with use. When supplying a customer with a new set of fuel injectors, flow check them to make sure they are all flowing within 2-3% of one another. If the flow rate varies by too much from injector to injector, the engine will cause drive-ability problems. As the fuel injectors get dirty, there will be a gradual loss of drive-ability and power. Not all injectors will get dirty at the same rate, so drive-ability can be lost in this way too.

Cleaning the Fuel InjectorS If the fuel injectors are restricted or leaking, there are several options to clean them including: 1. A fuel injector-cleaning chemical that is poured into the fuel tank. Provides a noticeable difference in power and drive-ability after one use. The disadvantages are that you can’t check the spray pattern, and the filters may become plugged with contaminants freed by the cleaner.

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2. A cleaner that runs through the Uses stronger chemicals that the in tank cleaners.

fuel

rails

and

injectors.

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3. An ultrasonic injector cleaner and injector flow bench. The preferred method of cleaning injectors. Cycles the fuel injectors while the fuel injector tips are immersed in an ultrasonic bath, which uses an environmentally friendly cleaning fluid to clean the fuel injectors. The flow bench portion also allows a user to perform a flow test before and after cleaning, and it allows the user to observe the fuel injector spray pattern. This method requires that the fuel injectors be removed from the engine.

Preventing Dirty Fuel Injectors Using gasoline that is infused with detergents to clean the fuel injectors while the engine is running. Some of these products even have formulations to help protect the fuel system against the corrosive effects of sulfur that is commonly found in today’s gasoline. These harmful sulfurs can corrode the fuel level-sending unit in the tank and cause the fuel level gauge to malfunction.

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The purpose of cleaning and flow-testing is to 1) remove any contaminants inside or outside the injector that impede fuel flow or degrade fuel spray pattern 2) to accurately measure each injector's fuel flow ability and 3) acquire quantitative data on injector performance the vehicle owner can use in matching injectors or tuning the engine's fuel system. Any set of fuel injectors will benefit from RC Engineering's clean and flow service, This is even true of new injectors because the individual-injector and system-total fuel flows must be known for performance tuning purposes. It is 5

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not uncommon for a set of original equipment (OE) injectors to have an unacceptably wide range of fuel flow and it's possible to even have new injectors that do not function properly. RC's standard testing process identifies those problematic injectors. The test process is as follows: first, your injectors are installed on RC Engineering's custom- designed-and-built, computer-controlled injector flowtesting equipment. A unique, non-flammable, gasoline-like test fluid is pumped at a precisely-controlled pressure through the injectors while they are pulsed by injector-drivers built into the equipment. The volume of fuel passed through the injector is accurately measured for a set amount of time and from those figures, fuel flow is derived. During the flow- test, the injector spray patterns are visually inspected and analyzed by RC's technicians using both bright room and strobe lights. After the initial flow-test, your injectors are transferred to an ultrasonic cleaning machine and connected to injector drivers. They are submerged in cleaning solution and pulsed while being subjected to ultrasonic waves. The combination of the solution and the ultrasound aggressively clean the internal and external parts of the injectors. Finally, the now-clean injectors are reinstalled on the flow-tester and run again. At the conclusion of the test, a printed report is produced. This report lists: fuel flow rates (in pounds-per-hour and cubic centimeters per minute) before and after cleaning, and spray pattern assessments for each injector tested. Also included is the "system balance" number which is the flow difference, expressed in a percentage, between the injectors having the highest and lowest flow rates amongst the lot of injectors tested. The system's total fuel delivery in lbs/hr. and cc/min along with a computation of potential horsepower at three different brake specific fuel consumption rates concludes the report.

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