Engine is alterable spiracle when technology (VVT, principle of Variable Valve Timing) is the moving circumstance according to engine, adjust into, capacity, spiracle leaves combine time and point of view. The empty tolerance of intromit is achieved optimal, improve combustion efficiency.
Use the performance that deserves to enrage time orgnaization to be able to improve engine changeably. Engine rotate speed is different, the requirement matchs gas differently to time. Because be changed when engine rotate speed,this is when, because enter the waste gas velocity of flow of air velocity of flow and compulsive exhaust period to also be changed subsequently, air current is used during because this is in,spiracle evening closes inertial increase into gas and the effect of stimulative exhaust to will differ. It is when car engine when low speed movement, air current is inertial small, if match gas to time right now,keep changeless, enter gas to will be rolled out by the piston partly cylinder, make decrease into tolerance, the residual gas inside cylinder will grow in quantity. It is when engine when high speed movement, air current is inertial big, if increase horn of the lag that take energy of life and spiracle angle overlap right now, can increase into tolerance to mix reduce residual gas amount, make the gas exchange process of engine attain at perfecting.
1. Bie Kejun jumps over VVT system to form
System of VVT of engine of 2.4L of the Jun Yue that fasten a gram basically controls position of module, camshaft to carry out by sensor, engine implement reach camshaft position to carry out implement composition of electromagnetism a powerful person, if pursue,1 is shown. System of Jun Yue VVT is a kind electronic-controlled hydraulic pressure runs unit, use at enhancing all sorts of engine function and serviceability. These buildup include to enrage dilute of pressure boost, exhaust to be discharged in order to reduce through be being entered in firebox, the engine torque range with bigger output and improve fuel economy. VVT system coverts through changing the camshaft angle to crankshaft position or when will achieve this goal.
Graph principle of 1 work of system of VVT of engine of the Jun Yue that fasten a gram pursues
During 4 stroke engine circulates, camshaft position is carried out implement make be mixed into gas only earlier or exhaust valve is later open, but the duration that cannot change spiracle to open or valve rise Cheng. Shut in engine, during fast condition and engine stop engine idle, camshaft is carried out implement maintain quiting the position. Camshaft position is carried out implement the interior of assembly has a return spring and lock to sell. During camshaft is not phasing mode, return spring turns camshaft time quit the position, and the lock is sold will carry out camshaft position implement chain wheel is fixed to camshaft. VVT system controls module by engine (ECM) control. Engine control module sends a signal to be carried out to camshaft position implement electromagnetism a powerful person, so that control flows to cam,carry out implement the discharge of engine engine oil of the passageway. Engine oil can transmit the engine of pressurization to be sold to the lock, make its loose, transmit carry out to camshaft position implement blade and rotor assembly place. Engine oil sheds the passageway that differs via two, a passageway is used at cam to shift to an earlier date, a passageway is used at cam defer. Cam is carried out implement fixed go up in camshaft and hydraulic pressure drive is moved, in order to change camshaft posture to crankshaft position (the angle of CKP) . Pressure of engine engine oil (EOP) , viscosity, temperature and oil level of engine engine oil may be right cam is carried out implement function has adverse effect. If the graph is shown 2 times,the oil pressure when VVT system works is flowed to.
Oil path of system of graph 2 VVT is controlled
Pass above structure and action analysis, VVT fastens unified dawn occurrence breakdown to be able to cause engine to cannot be started, or although can be started, engine is quickened undesirable also, in the meantime, the engine trouble lamp on appearance dial and TCS call the police the lamp illumes. If worker worker of a lot of maintenance does not understand VVT system breakdown to be able to bring about TCS to call the police lamp bright reason, can take roundabout way when removing trouble. The author shows this issue below with particular case.
2. breakdown example: Breakdown of system of V V T brings about TCS breakdown lamp to shine
A 2010 paragraph new supreme ruler jump over a car, equipment LAF2.4L erupts 4 crocks continuously motive, embarking GF6 6T45E 6 fast automatic transmission, travel course of development is 135 000km. Car advocate after mirrorring this car to drink water in engine, start, bring about engine connecting rod, valve to press a turn. Considering maintenance cost, car advocate drive the car " roadside inn " undertake maintaining, the engine after maintenance is finished starts difficulty, although can be started, but engine is met very quickly again flameout, at the same time the engine trouble lamp on dashboard, TCS calls the police the lamp illumes.
Receive the test-drive after the car, the author discovers this car dashboard shows " engine power is insufficient " and " overhaul traction to control a system please " wait for model of written characters. Join breakdown diagnoses instrument KT300, read take engine to control unit malfunction code, displayed 4 malfunction code, if pursue,3 are shown. Had undertaken heavying repair considering this car engine, then we examine this car sensor and case of connection of engine wiring harness first. Through microscope discovery this car enters outlet of sensor of exhaust camshaft position to insert turned over, outlet of sensor of position of the camshaft that take energy of life is inserted on sensor of exhaust camshaft position, outlet of exhaust camshaft sensor is inserted on sensor of position of the camshaft that take energy of life. Correct engine is started again after outlet of camshaft position sensor, start function to be started normally, and can idle fast move, but footplate of one step on the gas, engine with respect to flameout.
Graph malfunction code of engine of 3 breakdown car
Read again take engine to control module malfunction code, indication P0011, P2122, P2127 3 malfunction code. Read take engine to control data of sensor of module camshaft position to flow, discover in idle fast circumstance falls, position of the camshaft that take energy of life is carried out implement data of electromagnetism a powerful person is 0, exhaust camshaft position is carried out implement data of electromagnetism a powerful person is 45.5. Below normal circumstance, carry out into exhaust camshaft position implement data of electromagnetism a powerful person should be same.
According to data shedding we judge position of the camshaft that take energy of life to carry out implement electromagnetism a powerful person may damage, tear open positions of next the camshaft that take energy of life to carry out implement electromagnetism a powerful person (plug white) , enrage camshaft position to carry out via checking discovery to enter implement on mesh of electromagnetism a powerful person particularly dirty, the lotion that use Qing Dynasty is cleaned hind outfit answer, test-drive, breakdown as before. Change a position of new the camshaft that take energy of life is carried out implement after electromagnetism a powerful person, malfunction code still cannot keep clear of.
According to the structure of system of this car VVT and working principle, we suspect position of the camshaft that take energy of life is carried out implement the likelihood has a problem, change again then a chain wheel of new the camshaft that take energy of life (camshaft position is carried out implement installation is inside chain wheel) , read after test-drive again take engine to control module malfunction code, malfunction code of indication P2122, P2127. Right now, lamp of trouble of the engine on appearance dial illumes, TCS calls the police the lamp goes out.
Consult circuit of sensor of position of footplate of this car accelerator, discover sensor of position of footplate of this car accelerator controls module to arrive from engine X108 of by way of of sensor of accelerator footplate position and X200 two connector. X108 is in accumulator lower part, if the graph is shown 4 times; X200 is inside plaque of glue of A column ground, if pursue,5 are shown.
Graph the 4 X108 connector that are located in accumulator lower part
Graph the 5 X200 connector that are located in A column to fall
Unplug next X108 outlet, block with avometer ohm measure X108 connector " 3 " date terminal and " 5 " date terminal and outlet of sensor of accelerator footplate position " 1 " date terminal and " 2 " the resistor between terminal of number power source, via detecting resistance is less than 0.5 Ω , this explains breakdown of depress of report of power source of sensor of position of footplate of this car accelerator and circuitry may have nothing to do. But the discovery when checking outlet of sensor of accelerator footplate position, outlet of sensor of position of footplate of this car accelerator " 1 " lead and " 2 " the join with date factitious lead is together, and discovery has an additional black line join is on wiring harness of sensor of accelerator footplate position, down the trend of this black line, discover this black line entered connector X200. We get on this black line from wiring harness of sensor of accelerator footplate position the test-drive after unlock, engine is started smoothly, footplate of step on the gas, engine rotate speed rises smoothly. Ravel the plaque below A column, discover this car installed system of location of guard against theft. Because this car heavies repair,be so when, accumulator cuts off the power, system of location of guard against theft is effective bring about signal of sensor of accelerator footplate position to forbid.
This car primary failure reason is VVT system occurrence breakdown, bring about the TCS on appearance dial to call the police the lamp illumes, if do not understand VVT system to be able to be affected to TCS system, maintenance is versed in the likelihood can suspect TCS system has a problem. Jump over a car to go up in Bie Kejun actually, TCS calls the police the breakdown reason with bright light has a lot of kinds, but concern with engine more, the mainest reason has the following kinds:
(1) camshaft position is carried out implement breakdown of electromagnetism a powerful person;
(2) engine engine oil is smudgy jam mesh of electromagnetism a powerful person;
(3) camshaft position is carried out implement (chain wheel) impeller wears away cause oil pressure leak;
(Door of 4) solar term is smudgy, degree achieve 20% , start trouble of TCS of Electromechanical head miscarriage of justice;
(5)TCS system breakdown.
Actually, the malfunction code related to VVT is very much, for example P0010, P0011, P0012, P0013, P0014, P0016, P0017, maintenance rises more troublesome, as a maintenance technician, most the principle of at least is to be below the circumstance of ambiguous breakdown reason, do not want light light replaceable assembly. Although,replace a part repair breakdown, you also won't understand the reason that breakdown produces. Right way is: Get the structure that understands this system and working principle first, the circuit graph that integrates this system next reachs the diagnostic flow on maintenance manual, purposeful sexual ground goes checking.
