Honda Civic/Acura Integra

since 1994 release

Repair and operation of the car

The VTEC systems – the general information and check of a condition of components

General information

Many of models of the Honda cars are equipped with electronic system of correction of phases of gas distribution (VTEC).

Distinction between the ordinary engines and engines equipped with the VTEC system consists in a complete set and the principle of operation of the valvate mechanism. A design of the block of the engine and all hinged knots and units, and also schemes of the organization of lubrication systems and cooling on both units are identical. The engine which is externally equipped with the VTEC system differs in existence from above on a cover of a head of cylinders of a convex inscription of the corresponding content (VTEC).

The inlet camshaft is equipped with three cams for each of the valves given by it. The special module of management of the power (RSM), proceeding from the data arriving from information sensors defines what of sets of cams has to bring inlet valves of combustion chambers into each present situation. On the basis of the analysis of the arriving information of RSM includes or switches off the VTEC system.

As the initial parameters defining functioning of VTEC the following is used:

   a) Frequency of rotation of the engine (rpm);
   b) Speed of the movement of the car (miles/h);
   c) Output signal of the sensor of provision of a butterfly valve (TPS);
   d) The current load of the engine determined by indications of the sensor of absolute pressure in the inlet pipeline (MAR);
   e) Temperature of cooling liquid.

At small turns of the engine both primary, and secondary inlet valves work from own cams and open on identical height and with an identical duration, providing good torque in the lower range of turns and the high speed of reaction to gas.

When there is a need for increase in return of the engine, yokes of primary and secondary inlet valves by means of the special hydraulic device with electronic control are blocked with an intermediate yoke. At the same time duration and height of opening of both valves is defined by a form of the intermediate cam differing in the bigger height and smaller pointedness of rise.

Primary and secondary yokes cease to contact to own cams until the system is not disconnected. The system allows to try to obtain optimum torque both at small, and at high turns of the engine, depending on the current loading enclosed to it.

Check of a condition of components

Electromagnetic valve of blocking / датчик-выключатель pressure

The electromagnetic valve of blocking of the VTEC system including the sensor switch of pressure is located in the left part of a back wall of the engine (from a partition of a motive compartment).

Models 1994 and 1995 of of the issue.

Malfunctions in a contour of the electromagnetic valve of blocking of VTEC lead to registration of a code of malfunction (DTC) 21 in memory of the control unit. On the car dashboard at the same time the control lamp "Lights up check the engine". Detailed information on DTC systems of self-diagnostics are provided in the Head of the Control system of the engine.

The failure of the sensor switch of pressure leads to the record DTC 22 and operation of a control lamp "Check the engine".

Models since 1996 of the issue.

The refusal in contours of the electromagnetic valve or sensor switch of pressure leads to operation of a control lamp "Check the engine" and records in memory of the DTC P1259 control unit. Reading of diagnostic codes requires the OBD II scanner (see the Head of the Control system of the engine).

All models

PERFORMANCE ORDER

1. Disunite the round electric socket on two pressure (see an accompanying illustration). 2. Connect an ohmmeter between sensor switch plugs. The device has to record conductivity existence (zero resistance), otherwise the sensor switch is subject to replacement. 3. Connect the voltmeter between the mass of a body and the plug of a blue-black wire in the socket е from a plait. At the included ignition (a key in position of ON) the device has to show 12 V, otherwise check a condition of a blue-black wire and reliability of its contact connections on the site between the socket and the plug for RSM. 4. If check of tension yields positive result, connect the voltmeter between two plugs of the socket from a plait (blue-black and black wires). At the included ignition the device has to record 12 V, otherwise check a condition of a black wire (grounding) and reliability of its contact connections on the site between the socket and weight. 5. At the switched-off ignition (a key in position of OFF) disunite the 1-contact socket of the electromagnetic valve of blocking of VTEC (see an illustration above). Connect an ohmmeter between the valve plug (not the socket) and mass of a body. If instrument reading exceeds the limit of range from 14 to 30 Ohms, replace the electromagnetic valve (see below). 6. Turn out a bolt on 10 mm from the control union of pressure of oil on the electromagnetic valve. Connect to the union the mechanical manometer for measurement of pressure of oil (see an accompanying illustration). 7. Warm up the engine up to the normal working temperature (the cooling system fan has to work). 8. Short breakthroughs serially lift engine turns to values 1000, 3000 and 5000 in a minute. Consider the indication of the manometer at each of the listed frequencies of rotation of the engine. It is not necessary to lift engine turns without loading more than for one minute. 9. Pressure of oil has to be not above 0:49 kgfs/cm 2, otherwise it is necessary to check a condition of the electromagnetic VTEC valve. 10. Connect a wire crossing point between the positive plug of the battery the plug of the electromagnetic VTEC valve (see an illustration to paragraph 1). For a short time lift engine turns to value 5000 in a minute (no more than for one minute) and consider the indication of the manometer. This time it owes not less than 4.2 kgfs/cm 2, otherwise check a condition of the valve. 11a. Remove assembly of the electromagnetic valve, separate from it pressure sensor switch. 11b. Manually check freedom of the course of a plunger (see accompanying illustrations). At assembly installation into place do not forget to replace a sealing ring. 12. Check a state and passability of a full-line oil filter. Clean the filter and install it on the place (with a new sealing ring). If passability of the filter is broken, replace motive oil.

Yokes with masloraspylitel

PERFORMANCE ORDER

1. Uncover a head of cylinders (see the Equipment and governing bodies in salon) and bring the piston of the first cylinder into the provision of VMT (see Adjustment of seats). 2. Press a finger an intermediate yoke (see an accompanying illustration) – it has to move freely from yokes of primary and secondary valves. Otherwise remove yokes for the purpose of check of a condition of components of assembly (see Removal, check of a state and installation of camshafts and collectingки yokes). 3. After removal of yokes (see Unlocking of a cowl) take from them the synchronizing pistons (see an accompanying illustration). A) Yoke of primary valve C) Yoke of the secondary valve C) Intermediate yoke D) Short piston E) Long piston 4. Check all components (yokes and pistons) for existence of signs of wear, zadir and traces of an overheat. Replace defective parts. Remove masloraspylitel from the inlet and final parties of a head of cylinders (see an accompanying illustration), clean them and establish into place. 5. Assembly is made as it should be, the return to a dismantle order. Before installation of sets of yokes on an axis bring together them and fasten with rubber bandages (see Unlocking of a cowl).

Assemblies of proofreaders of valvate gaps

PERFORMANCE ORDER

1. In a head of cylinders four sets of proofreaders of valvate gaps are established. 2. Remove individual assemblies of proofreaders (see Unlocking of a cowl). 3. Fingers check freedom of movement of a plunger of assembly of the proofreader (see an accompanying illustration) – insignificant resistance has to be felt, however at increase in loading the plunger has to be wrung out freely. In case of detection of defects replace assembly.