I. Identification of car failures
In doing so, the customer should be interviewed with a view to obtaining an accurate picture of the failure and the conditions it produces, as well as the severity of the symptoms
1. Has the failure been ongoing or has it occurred at times? Is there a pattern when it comes? Is it still happening
2. Has the failure occurred at specified times, such as acceleration or ramping, or at specified temperatures (e. G. Cold or heat)
3. What are the symptoms: voice, vibration, smell, performance failure, or any combination of the above
4. Have any previous failures occurred and what measures have been taken to repair them
When was the last car repair? What measures were taken to repair them
Ii. Identification of failures
The way customers describe symptoms may differ from you, and it is best to experience them by driving。
It is also important to remember that there is no failure without symptoms. Don't try to repair it if you don't experience the symptoms of failure. Unpurposed work will only waste you much time and energy in vain. The failure should therefore be confirmed prior to the commissioning of the failure。
Iii. Inspection of the mechanical component
1. Check for obvious defects and remove some simple malfunctions. Connection plugs, vacuum tubes, oil, coolant, drive belts。
Battery voltage. Static open circuit voltage: should not be less than 12. 2 v; engines should not be less than 13. 5 v. When engines operate, readings should be less than 14. 5 volts. High exchange voltage can cause damage to the diode of the exchange generator。
Three conditions for engine work: fuel supply, compression and ignition. These failures are often mistaken for control systems. Recent electrical control systems have self-adaptation memories that can correct such misunderstandings and allow hidden mechanical malfunctions to emerge. If you want to check the electrical control system to find out why it's malfunctioning, it'll only make you a little bit worse。
(1) fuel supply
(b) installation of pressure sheets to check fuel pressure: toyota is 230 - 260 kpa
(a) checking the oil supply of the oil pumps: more than 21 kpa over fuel fuel
Fuel quality: brands, impurities
(2) compression
The best way to check combustion chamber containment and basic engine work is to conduct compression ratio tests. Test it with a cylinder pressure table。
(3) fire
Check the secondary voltage of the ignition ring (10-20kv) and determine whether the basic ignition is on time and in advance of the ignition (8°). The best way to check the ignition system is to conduct an oscillometric curve analysis. A detailed description of the oscillator curves used to analyse ignition systems will be provided later in this book. There are also ignition sequence tests (1-3-4-2)。
(iv) understanding the system
While electrical control systems work in similar ways, each system is unique. If the failure is electronic, you should be fully aware of the particular system involved. You can consult the original plant instructions or some reliable post-sale information, such as:
