Maintenance of throttle valve

The main cause of throttle scaling is oil and gas, followed by particles and moisture in the air. In other words, using qualified air filter and removing the crankcase ventilation pipe will slow down the scaling speed of throttle valve. The crankshaft is built in the crankcase, and the lower part is connected with the oil bottom. The working temperature of this part is about 100 ~ 180. Oil will volatilize when used. The longer it takes, the higher the temperature and the stronger the volatilization. In addition, the compressed gas in the cylinder will squeeze into the crankcase through the gap of the piston ring, so there must be a channel for the gas to escape, otherwise the oil bottom will form a positive pressure (see the related article in Nightcrawler for details). The reason why the crankcase ventilation pipe is connected to the throttle valve is the requirement of environmental protection on the one hand, and the gas is pumped out of the crankcase by using the negative pressure of intake air on the other hand. When the oily steam reaches the intake pipe and cools, the oil in it will condense on the intake and throttle valve, and then the carbon deposit in the steam will also be deposited on these parts. Because the gap where the throttle valve is opened has the largest air flow, small space and low gas temperature, this part is the easiest to condense.

Therefore, how long the throttle will be dirty depends on the quality of the air filter, the brand and quality of the engine oil, the condition of the driving section, the temperature, the working temperature of the engine, driving habits and so on. Even for individuals, it is impossible to determine the time to clean the throttle with a fixed number of kilometers. The interval between cleaning the throttle for the first time in a new car is the longest. Later, due to the continuous condensation of oil and gas in the crankcase ventilation pipe and intake port, the cleaning frequency will increase, and different weather conditions will also affect the dirty speed of the throttle.

Throttle valve failure

General introduction

The composition of electric throttle can be roughly divided into the following parts: throttle, electromagnetic driver, potentiometer, controller (some not, directly managed by ecu, bypass valve. Its fault characteristics are divided into two categories: hard fault and soft fault. Hard fault refers to mechanical damage, and soft fault refers to dirt, maladjustment, etc.

hard failure

The resistance part of potentiometer is formed by spraying a layer of carbon film on polyester substrate, which is actually a very low-level preparation process with low wear resistance. To put it bluntly, it is not as good as the potentiometer we usually add! The sliding contact consists of a row of opposing claws made of fine steel. Attention! It's claws! This is simply worse! In addition, there is no protective agent on the carbon film, and the falling toner leads to poor contact, which is inevitable! I once repaired a scraped carbon film, 70 thousand kilometers, and the master's feet were owed!

Soft fault

People often worry about cleaning the throttle, because most of the time the throttle is too low. Air flows through the gap of the throttle at high speed (tens to hundreds of meters per second), and the influence of dust on the airflow exceeds the adjustment ability of the throttle.

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