Note. The following procedure assumes that the ignition distributor is installed correctly. If you need to set TDC to install a distributor, the piston position can be determined using the method described below for models without a distributor (release since 1998).
1. Top dead center (TDC) - the uppermost position of the piston in the cylinder, which it can occupy when the crankshaft rotates. In a four-stroke engine, each piston goes to TDC twice during the operating cycle - at the end of the compression stroke and at the end of the exhaust stroke. Usually it is TDC on the compression stroke.
2. The installation of pistons at TDC is necessary when performing many repair and adjustment work, such as removing and installing parts of the gas distribution and ignition mechanism.
3. Before starting this operation, set the transmission to neutral and block the rear wheels, for example, by applying the handbrake. Also turn off the ignition system by disconnecting the low voltage wires from the ignition coil (see chapter 5). Also remove the spark plugs (see chapter 1).
4. To set any piston to TDC, turn the crankshaft in one of the following ways. The normal direction of rotation of the crankshaft is clockwise when looking at the engine from the pulley guard.
- A) The most common way to rotate the shaft with a thorium key, put on a non-end shaft, screwed into the toe of the crankshaft.
- b) You can use the remote starter switch. If you have such a switch, use it in accordance with the manufacturer's instructions. Bring the crankshaft close to the TDC position, then tighten it with a wrench, as described above.
- V) You can ask an assistant to turn on the starter with the ignition key in short pulses. In this way, you can turn the crankshaft close enough to the TDC position, and then tighten it in the way (A). At the same time, make sure that the assistant removes the ignition key from the lock and gets out of the car.
1997 and earlier models
5. Find on a cover of the distributor of ignition an output corresponding to the cylinder No. 1. If the leads on the cap are not marked, trace the high voltage wire from the spark plug to the cap.
6. Mark with a felt-tip pen or chalk the cover and the distributor body opposite the output No. 1.
7. Remove the cap from the distributor and set it aside (if necessary see chapter 1).
8. Rotate the crankshaft until the notch on its pulley matches the TDC queen on the advance setting scale (pic. 3.8).
9. Look at the ignition distributor rotor. It should be directed exactly at the mark you made on the case.
10. If the rotor is rotated 180°relative to the mark, then piston No. 1, although it is at TDC, is finishing the exhaust stroke.
11. To bring #1 piston to TDC on the compression stroke, rotate the crankshaft a full turn (360°) clockwise. Now the distributor rotor should turn towards the mark. If the distributor rotor points to spark plug No. 1, and the mark on the crankshaft pulley matches the pointer, then piston No. 1 is at TDC on the compression stroke.
Note. If the gel distributor rotor is directed towards the contact of spark plug No. 1, and the marks on the crankshaft pulley do not match, then the camshaft drive belt is not installed correctly.
Release models since 1998
12. Models since 1998 are equipped with a distributorless ignition system (see chapter 5). To install piston No. 1 at TDC, unscrew the spark plug from cylinder No. 1 and screw a compression gauge into the hole from under the spark plug.
13. Turn the crankshaft (see item 4 of this paragraph). As the piston approaches TDC on the compression stroke, the pressure recorded by the compression gauge will begin to increase. Continue turning the crankshaft until the pointer on the crankshaft pulley aligns with the TDC mark (see fig. 3.8). After the pressure starts to rise, do not turn the crankshaft more than necessary to align the marks.
14. It may take up to two other revolutions of the crankshaft to set the piston to TDC on the compression stroke. If during the first revolution the pressure does not begin to rise, continue to rotate the crankshaft. If there is pressure and the marks match, then piston No. 1 is set to the desired position.
All models
15. After the No. 1 piston is set to TDC on the compression stroke, the remaining pistons can also be set to TDC. by turning the crankshaft in 120°increments and observing the order of operation of the cylinders (i.e., an additional rotation of not 120°will result in TDC piston No. 2, etc.).