Honda Civic/Acura Integra

since 1994 of release

Repair and car operation

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

General information

Some of models of Honda cars are equipped with electronic system of correction of phases of a gazoraspredeleniye (VTEC). On the Civic models the VTEC system of one of two various types (by VTEC and VTEC à) can be used.

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

The onboard processor of the models equipped with VTEC system is capable to correct phases of operation and size of opening of inlet valves at the expense of use of various size of cams of a camshaft. The processor, depending on data arriving from the information sensor, either includes, or switches off system.

As initial parameters for VTEC systems of both types the following is used:

  a) Frequency of rotation of the engine (rpm);
   b) Speed of movement of the car (mile/h);
   c) Target 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.

Configuration and principle of functioning of systems VTEC à differ from those for VTEC systems (see below) a little.

VTEC à (D16Y5)

The camshaft is equipped both primary, and secondary cams of a drive of inlet valves. Cams differ both in a form, and on height of liftings, i.e. the parameters defining duration and extent of opening of valves.

At small turns of the engine secondary valves work from own cams of a camshaft having very small lifting and a peaked form (i.e. valves are slightly opened only slightly and very much for a while), holding the sprayed fuel from consolidation in a head of cylinders. The good torque with high speed of response to gas thus develops.

If there is a need for increase of return of the engine, secondary yokes are blocked with primary by means of the special hydraulic device with electronic control.

Secondary yokes cease to contact to own cams up to that moment as the system will not be disconnected. Thus both valves open on full height and with the maximum duration, providing increase of turns and engine return.

VTEC (D16Y8)

Cams of a drive of primary and secondary inlet valves of a camshaft in this system are identical in a form and height of liftings. Between them the additional third cam called by the also intermediate is located. These intermediate cams differ in bigger height and a smaller sharpness of lifting that provides big size and duration of opening of the valve.

At small turns of the engine both primary, and secondary inlet valves work from own cams and open on identical height and with identical duration (unlike system VTEC à). When there is a need for increase of return of the engine, yokes of both inlet valves by means of the special hydraulic device with electronic control are blocked with an intermediate yoke. Thus duration and height of opening of both valves is defined by a form of the intermediate cam, differing bigger height and a smaller ostrokonechnost of lifting.

Primary and secondary yokes cease to contact to own cams until the system will not be disconnected.

The system allows to achieve an 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

Proof-readers of klapanny gaps (only VTEC)

Four proof-readers of klapanny gaps are placed in holders, forming similarity of hydraulic pushers.

PERFORMANCE ORDER

1. To Otboltita also remove assembly of the holder. 2. Take from the holder of assembly of individual proof-readers. 3. Fingers check freedom of moving of each of proof-readers. In case of identification of points of a zakusyvaniye replace defective assemblies.

Plate of distribution of phases, plug and returnable spring (only VTEC à)

Four plates of distribution of phases with returnable springs (see an illustration below) are planted in holders of a camshaft on an axis of inlet yokes.

А) Plate of distribution of phases В) Returnable spring С) Holder of a cam

Apparently from an illustration, the plug of assembly is equipped with a coat hanger for spring deduction.

PERFORMANCE ORDER

1. Check reliability of fastening of a spring on the holder of a camshaft and a plate of distribution of phases. 2. Examine components on existence of scratches, cколов, traces of an overheat and other damages. 3. Defective details are subject to replacement. 4. The assembly order is clear from an illustration above.

Synchronizing assemblies

PERFORMANCE ORDER

1. After removal and dismantle of assemblies of yokes (see. Removal, check of a condition and installation of assembly of yokes), take also components of synchronizing knots (see accompanying illustrations). Only VTEC à D16Y5: А) Yoke of the primary valve В) Yoke of the secondary valve С) Blokirator piston D) Blokirator spring Е) The synchronizing piston Only VTEC D16Y8: А) Yoke of the primary valve В) Yoke of the secondary valve С) Intermediate yoke D) Synchronizing pistons 2. Check a condition of a blocking spring (only VTEC à). 3. Examine other components of assembly (a yoke with synchronizing pistons). In case of identification of signs of wear, attritions, deep scratches, задиров or overheat traces, replace defective components. 4. Assembly is made as it should be, the return to a dismantle order. Gather components of assemblies of each of cylinders, fasten them a rubber bandage, after it establish on an axis (see. Removal, check of a condition and installation of assembly of yokes).

Electromagnetic valve of blocking of VTEC

Malfunctions in a contour of the electromagnetic valve of blocking of VTEC lead to operation of a control lamp “Check the engine” on the car dashboard. At the same time in memory control units the code of malfunction (DTC) Р1259 is brought. On a design the valve of blocking of VTEC with the built-in sensor switch of pressure is similar used in VTEC system of the Integra models. The description of procedure of check of serviceability of functioning of assembly is provided in the Part engine Repair without extraction from the car - the Integra models of the present Chapter.

Masloraspylitel

See. Removal, check of a condition and installation of assembly of yokes.

Yoke of the primary valve

See. Removal, check of a condition and installation of assembly of yokes.

Yoke of the secondary valve

See. Removal, check of a condition and installation of assembly of yokes.

Intermediate yoke (only VTEC)

See. Removal, check of a condition and installation of assembly of yokes.

Intermediate cam of a camshaft (only VTEC)

See. Removal, check of a condition and installation of assembly of yokes.