Installation of the piston of the first cylinder in TDC

Gas distribution mechanism on cars Golf III is rotated by the crankshaft belt camshaft drive (on some engines through the intermediate shaft).

If during the maintenance of your car, for whatever reasons, the belt drive of a (interim) of the shaft has been removed, it is necessary to synchronize their rotation.

To avoid damage to the valves during engine overhaul, removing the cylinder head, and so on., To the removal of the timing belt using the marks specified by the manufacturer, it is necessary to establish the piston number 1 in its top dead center. In a four-stroke engine the piston reaches top dead center twice per cycle of operation: in the compression stroke and the exhaust stroke. It is generally accepted to determine the TDC number 1 cylinder on the compression stroke. At the family car Golf III / Vento is a cylinder - the closest to the timing belt.

If the timing belt is not removed, the installation of the piston at TDC number 1 is conducted as follows:

- Park the vehicle on level ground, secure it with the parking brake and stops the wheels, and then switch the gear selector in the neutral position;

- Remove the top cover of the outer belt camshaft drive to gain access to the toothed belt pulley;

- Disconnect the negative terminal of the battery, remove the central high-voltage wire, close it in the engine block;

- Mark on the body of the distributor of ignition high voltage terminal position of the cylinder number 1 distributor cap;

- Remove the ignition distributor, disconnect high-voltage wires from spark; if necessary, to remember the order of their connection; You can unscrew the spark plug - this will facilitate the rotation of the engine;

- Rotate the crankshaft in its normal direction of the crankshaft pulley bolt with a wrench to face head. When the contact of the distributor rotor begins to approach the label that has been made on the distributor ignition timing marks get (fig. 2.31) on the camshaft and a pulley on the inside of the cover belt (the cylinder head cover - depending on the design). Continue to rotate the crankshaft clockwise until the labels are not exactly aligned with each other;

- Find marks on the crankshaft pinion (or grooved pulley) and on the cover of the camshaft drive belt (or intermediate shaft); make sure they are properly aligned (Fig. 2.31, 2.32, 2.33, 2.34, 2.35, 2.36, 2.37);

- ABF on engines and AEK get on the gearbox casing opening to variable valve timing, remove the plug, then it becomes visible edge of the flywheel, which has several labels. Align the marks of the camshaft, and the marks on the flywheel housing with a pointer to the box. Note that an accurate result, looking at the mark in a direction perpendicular to the plane of the opening in said housing box. Also take into account that the engine AEK countershaft sprocket has no labels - align contact center rotor distributor Tagged terminals candles number 1 on the distributor of ignition;

- Ensure that the contact center slider in the ignition distributor accurately aligned with the label terminals cylinder number 1 on his body. If the slider is not aligned with the terminal number 1 in the combination of adjusting labels camshaft, refer to the chapter, which deals with the ignition system of the engine; Check whether the valve is installed, not "jumped" to whether one or more teeth of the camshaft drive belt (s);

- If all these steps are fulfilled and all the labels fully compatible, the first cylinder of the engine installed in his TDC. If you are going to remove the timing belt, to maintain a consistent rotation of the crankshaft, camshaft and intermediate shaft which exclude whatever movement pulleys relative to each other.

If the timing belt is removed (for example, in the case of complete disassembly and overhaul of the engine), the installation of the piston at TDC number 1 held otherwise.

To avoid collision of the piston and valve, entailing the likelihood of damage to the engine, just follow the sequence described below:

- Before installing the cylinder head crankshaft set so that all four pistons are in the middle of its stroke cylinders, the piston number 1 must be in the position corresponding to the course of the compression, - approximately 90 ?� BTDC. Then find the mark on the camshaft pulley and on the inside cover of the camshaft drive belt or a cylinder head cover (see. Fig. 2.31-2.37);

- Rotate the camshaft pulley in its normal direction of rotation until the precise combination of labels on a gear pulley and the inner cover of the camshaft drive belt or a cylinder head cover (engine ABF);

- On engines AEK make any contact center combined runner distributor of ignition with a tag number 1 cylinder terminals on the distributor, and if they are not aligned, turn the intermediate shaft sprocket to the precise alignment;

- Find marks on the crankshaft pinion (on the grooved pulley) and on the cover of the camshaft drive belt (intermediate shaft) to rotate the crankshaft 90 ?� (a quarter turn) in the working direction of rotation and align the label;

- On engines and AEK ABF, if the motor is connected to the gearbox, the consistency of the rotation of the crankshaft and the camshaft, you can also check coincidentally marks on the flywheel and the gearbox: Remove the cover from the housing inspection opening and check coincidence of labels;

- Ensure that the contact center slider in the ignition distributor accurately aligned with the label terminals cylinder number 1 on his body. If the slider is not aligned with the terminal of the first cylinder at the setting mark of the camshaft, refer to the section, which deals with the ignition system of the engine; Check whether the installed ignition distributor;

- If all these steps are fulfilled and all the labels precisely aligned, then the first cylinder of the engine installed in his TDC. Up to exclude a belt installation whatsoever movement pulleys relative to each other.