Because the EFI motorcycle has a great change in structure compared to the carburetor motorcycle, once it needs to be maintained, it must be complex pipelines and joints in front of us! Many old maintenance masters will feel helpless for this new technology, but if we master some basic principles of new technology and follow some previous diagnostic techniques, we can accurately and quickly find out where the fault is!

1. Outside before inside

In the event of engine failure, the possible fault parts other than the electronic control system are checked first. This can avoid a fault that is unrelated to the electronic control system, but a complex and time-consuming inspection of the system's sensors, ECUs, actuators and lines, that is, the real fault may be easier to find but not found.

Taking the intake system as an example, the ecu mainly controls the amount of fuel injection according to the air flow measured by the air flowmeter or the intake manifold pressure measured by the intake pressure sensor, so the intake system seal is not strict and leakage will lead to engine imbalance, resulting in unstable idle speed, easy to stall, power and acceleration deterioration, and the impact on the system is much larger than that of the carburetor engine.

When diagnosing the fault of the intake system, first of all, it should be checked and excluded according to the basic diagnostic procedures without electric control components; If the fault is still not eliminated, and it is confirmed that the intake system has a fault, the air filter should be removed first, and the visual inspection should be carried out to eliminate some general fault factors. Check the following items:

1. Check whether there is dirt, impurities or other pollutants in and around the air filter element, and replace it if necessary.

2. Check whether the intake pipe is broken, leaky, aged or crushed.

3, check whether the sensor and the computer are connected to the wiring harness is loose or disconnected, whether the wire is worn or short circuit between the lines, the phenomenon of open circuit, whether the wire connector is plugged in place, there is no corrosion phenomenon.

4, check whether the sensor has obvious damage.

2. Simplify before you simplify

Possible fault areas that can be checked in a simple way are checked first. For example, intuitive diagnosis is the simplest, and we can use visual inspection methods such as looking, touching, and listening to quickly find out some of the more obvious faults.

Visual diagnosis does not find the fault, need to use instruments or other special tools for diagnosis, should also be easier to check the first inspection.

3. Cook before you grow

Because the structure and working principle of the EFI system is more complex, the EFI system of different models often has a large difference, in the inspection and elimination of the fault of the EFI system, it is necessary to understand the working principle and structural characteristics of the EFI system, refer to the detailed technical data of the model to be repaired.

In addition to the use of different environment and other influencing factors, a certain engine failure phenomenon may be the most common failure of some assemblies or components, should first check these common fault parts. If the fault is not found, check other unusual possible fault parts.

4. Code first

Because of the increasing complexity of the EFI system, it is more difficult to determine the fault location when a fault occurs. In order to facilitate maintenance, modern EFI motorcycles generally have fault self-diagnosis function. When the EFI engine is running, after the fault self-diagnosis system detects the fault, it stores the fault in the computer memory in the way of code, and alerts the rider through the warning light.

Therefore, the maintenance should be given priority to the fault diagnosis interface (socket) of the ecu, according to the specific program with manual crossover method or the use of fault diagnosis instrument, the fault code in the ecu memory is called out, and is displayed in the way of light flashing or directly by the diagnostic display screen in digital form, so as to help the maintenance personnel quickly and correctly determine the type and scope of the fault.

After the fault referred to in the fault code is eliminated, if the engine fault phenomenon has not been eliminated, or there is no fault code output at the beginning, then the engine is checked for possible fault parts.

After the fault is eliminated, the fault code stored in the ecu memory is also cleared by manual method or by means of diagnostic instrument according to specific procedures, so as to record and store new fault codes. If the old fault code is not removed, when the engine fails again, the ecu outputs the new and old fault codes together, so that the maintenance personnel do not know which is the real fault of the engine, which is the fault that has been eliminated before, so that the new and old fault codes are confused, and the maintenance is difficult.

5. Think before you act

As we all know, indiscriminate demolition can only turn small failures into major failures, and even cause irretrievable conditions, bringing undue losses. Therefore, it is necessary to first analyze the fault phenomenon of the engine, understand what the possible causes of the failure are, and then carry out the fault inspection.

Only in this way can the blindness of fault inspection be avoided: neither ineffective inspection of the parts unrelated to the fault phenomenon can be done, but also the omission of some relevant parts can be avoided and the fault cannot be quickly eliminated.

6. Supply before use

The performance of some components of the electronic injection system is good or bad, and the electrical circuit is normal or not, often judged by its voltage or resistance and other parameters. If there is no such data, the fault inspection of the system will be very difficult, and often only the method of replacement of new parts can be adopted, which sometimes causes the maintenance cost to soar and labor time. Therefore, in the maintenance, the maintenance data of the maintenance model should be prepared.

In addition to collecting and sorting out these maintenance data from maintenance manuals and professional books, another effective way is to use trouble-free vehicles to measure the relevant parameters of their systems and record them as the detection and comparison parameters for future maintenance of the same type of vehicles. If you usually pay attention to do this work, it will bring convenience to the fault inspection of the EFI system.

Special note: EFI engine failure does not necessarily occur in the EFI system. If the engine is found to have a fault, and the fault warning light is not lit (no fault code is displayed), in most cases, the fault may be unrelated to the EFI system, at this time, it should be as if the engine is not equipped with the EFI system, according to the basic diagnostic procedures for fault inspection.

(Graphic from the network, infringement please contact delete)