General information
1. Top Dead Center (TDC) is the highest point in the cylinder that the piston reaches during its forward motion during crankshaft rotation. Each piston reaches the TDC position at the end of the compression stroke and at the end of the exhaust stroke. It is generally considered that TDC corresponds to the position of the piston (usually cylinder #1) in the compression stroke. In some procedures, the engine position corresponding to TDC is a prerequisite. The marks on the torsional vibration damper, mounted on the front of the crankshaft, are associated with the position of cylinder #1 at TDC.
2. Cylinder #1 is located at the right end of the engine, in the rear section of the block. Cylinders #2 and #3 are also located in this section. Cylinder #4 is located at the right end of the engine, in the front section of the block.
3. Remove all spark plugs (chapter 1). To improve access to the crankshaft pulley, remove the front wheel and wheel arch poker.
4. It is best to turn the crankshaft with a wrench by the bolt of its pulley. It can also be turned with the starter (when an assistant turns the ignition key or with the help of a remote starter switch) to a position close to TDC, and then manually turn it with a wrench. After using the starter, it must be turned off immediately.
5. Turn the crankshaft clockwise to feel the compression in cylinder #1, temporarily plugging the spark plug hole.
6. Turn the shaft in the same direction so that the key of its pulley is in the 11 o'clock position. The timing mark on the pulley periphery should coincide with the mark (in the form of an arrow) on the timing mechanism cover. Nearby are arrows corresponding to the piston position before TDC at 10° and 30° (see Fig. 4.6, a, b).
7. If additional checking is required, the cylinder head covers can be removed (paragraph 6) and the position of the marks on the camshaft sprockets can be checked. These marks should be facing each other when cylinder #1 is at TDC (see Fig. 4.7).
8. After setting the piston of cylinder No.1 to TDC, you can set TDC in other cylinders by turning the crankshaft by 120° (at one time) and monitoring the firing order of the cylinders (see Technical requirements).