How to check nozzles?
Every motorist should know how to localize and eliminate the most common car faults. If the engine is difficult to start, if jerks or failures occur at increased load on the engine, if the engine is unstable idling or develops insufficient power, the problem may be hidden in the injectors. How to check nozzles?
Short educational program
The injector is a device that delivers certain doses of fuel to the engine, the injectors are mechanical and electromagnetic. Mechanical open under pressure and dosing as such do not produce, they simply spray the fuel, opening and closing the spray hole. Electromagnetic nozzles are a controlled valve that opens and closes under the action of an electronic control unit. Electromagnetic injectors are installed on the central and distributed injection systems. In the central injection, fuel is supplied by a single nozzle, which is installed in front of the throttle.In the case of a distributed injection, fuel is supplied through separate nozzles connected to the intake pipes of each cylinder. The central nozzle of the winding is low (4-5 ohms), distributed - high (12-16 ohms).
Principles of diagnosis
Checking the injectors of modern imported cars requires a special test bench. Domestic cars are less whimsical. How to check the nozzle vaz, for example? To do this, remove the fuel frame, disconnect the electrical connector and the bracket for mounting the fuel tubes to the receiver and check the operation of the injectors. Do-it-yourself nozzle check does not take much time. First, check the injector nozzle coil with a tester - resistance should be 11-15 Ohms. Connect the fuel tubes to the ramp and connect the connector of the nozzle assembly with the flasks under them. Scroll through the engine with the starter and watch the torches of the fuel - they must be the same shape. Scroll through the engine for a few minutes, and see if the flasks fill evenly under the nozzles. Ideally, the amount of fuel should be the same.To check the quality of the atomization of fuel, disconnect the electrical connector from the nozzle and apply 12 V to the battery, then turn on the ignition and watch the spray. Injection nozzles should create four jets. Any deviation from the norm leads to a malfunction. If the nozzle is different resistance, the shape of the torch, the number of jets and the speed of the fuel supply, it needs to be cleaned or replaced. When reassembling the injectors, make sure that the rubber sealing rings are not rubbed, torn or cracked, otherwise they need to be replaced.
Causes and troubleshooting
Now, when you know how to check the operation of the injectors, a natural question arises: why is their work disrupted? The most common cause of failure of the injectors - elementary pollution. Under the action of high temperatures, the nozzle is coked with resins that are present in low-grade fuel. At the nozzle, solid deposits are formed, blocking the spray holes and breaking the needle valve tightness. This problem can be solved in several ways:
- Fuel additives (prophylactic method and is only suitable if you use it regularly. When old deposits appear, it leads to the opposite result).
- Flushing without dismantling the flushing fuel (solvent).
- Flushing on an ultrasound bench is an extreme but fairly effective measure for removing solidified deposits.