Why is the overnight car idling high?
Some netizens responded that they would leave their car at the airport overnight when they were on a business trip.Then the problem comes, after the business trip……As soon as the overnight car starts, idle speed is directly 1400;There is no need to worry about flameout in gear, no need to step on the accelerator in gear shift, no step on the accelerator in third gear can reach 35 yards, and no speed in fourth gear can go up, which is obviously difficult;When the water thermometer comes up, the idle speed is just over 500.Is that what’s going on, or is spraying smart??Actually, this is normal. It’s called cold start.Engine wear and 90% occurred in low temperature, low temperature, especially after the car put a night inside the engine lubricating oil will be due to the factors of gravity flow back to the oil pan, at this point, if you start the engine, engine wear serious, in general, engine oil pump connected to the crankshaft and camshaft together, as long as the engine is running, the crankshaft rotation,Mechanical oil pump will quickly pump oil to the lubrication part, but, because of the high viscosity of oil in low temperature environment, low temperature liquidity, many parts of the lubrication by splashing poor lubrication effect.?After a night, when I started it at work the next day, I found that the speed always remained at 1200 RPM, while the idle speed was only 800 RPM when I normally drove. I didn’t need to worry about it. This was a control strategy specially set by our designer in the CPU to speed up the hot car.This can reduce the engine working time under poor lubrication conditions.It’s not an idle malfunction.?Because the car is cool when there are many disadvantages, so the engine computer will increase idle speed, increase the amount of fuel injection, when the water temperature rises as soon as possible.When the water temperature rises slightly, the idle speed decreases slowly, and the high idle state lasts about 1-2 minutes. The lower the water temperature, the longer the duration.How does the driving computer know it’s a cool car?It has a sensor, called the water temperature sensor, is to rely on it to real-time monitoring, too low will increase the amount of fuel injection, too high will alarm, directly displayed on the dashboard, light up the water temperature alarm lamp, once lit up, need to stop immediately.?Cold car, due to the low temperature in the cylinder, gas atomization is bad, in order to reach the condition of burning must, a chance to ask for an increase in the concentration of the mixture of oil and gas, so a chance to improve the idle speed, in order to increase fuel injection quantity and improve the concentration of the mixture of oil and gas, with the increase of temperature of the cylinder, already do not need too thick oil and gas mixture, so the idle speed gradually reduce,The amount of fuel injected into the engine is also gradually reduced, and when the engine temperature is completely normal, the ECU maintains an air-fuel ratio, which is the ratio of air to oil that burns completely.At this time, the engine enters closed-loop operation, and the fuel injection volume is no longer adjusted according to the water temperature sensor, but according to the level of the oxygen sensor in the ternary catalysis, so as to achieve the state of complete combustion emissions.