2. Piston installation (to her) TDC is an important part of many service procedures such as adjusting valve clearances and removing camshafts and sprockets/timing chains.
3. Before beginning this procedure, place the transmission in neutral, apply the parking brake, or chock the rear wheels. Also, shut off the fuel injection system by relieving fuel pressure (see chapter 4) and the ignition system by disconnecting the electrical connectors in the primary electrical circuit of the ignition coils (see chapter 5).
4. To bring any piston to the TDC position, rotate the crankshaft using one of the methods described below. When looking at the front of the engine, the normal direction of rotation of the crankshaft is clockwise.
- A) The preferred method is to turn the crankshaft using a socket and ratchet on the bolt on the front end of the crankshaft. Rotate clockwise.
- b) If you have an assistant who can pulse the ignition switch to the start position, you can bring the piston to close to TDC without the remote start switch. Make sure your assistant is out of the vehicle with no access to the ignition switch, and use a socket and ratchet to complete the procedure as described in paragraph above (A).
5. Remove spark plugs (see chapter 1) and install a compression gauge in the #1 spark plug hole (fig 3.5). It must be a device with a threaded connector and a hose at least 15 cm long.
Pic. 3.5. To help locate the TDC, you can insert a compression tester into the #1 spark plug hole
Pic. 3.6. Align the mark on the damper with the mark «IN» on the timing chain cover
6. Turn the crankshaft using one of the methods described above, while observing the pressure on the compression gauge. The moment at which the pressure gauge begins to show pressure indicates that the No. 1 cylinder has begun its compression stroke.
7. After the start of the compression stroke, TDC on that stroke is reached when the piston reaches the top of the cylinder.
8. Continue turning the crankshaft until the mark in the crankshaft damper aligns with the mark «TSS» (TDC) or «ABOUT» on the timing chain cover (fig 3.8). At this point, cylinder #1 is at TDC on the compression stroke. If the marks are aligned, but there is no compression, the piston was not in the exhaust stroke and the crankshaft should be rotated 360° (one turn).
Note. If you don't have a compression gauge, you can simply plug the spark plug hole with a blunt object and listen for compression as the engine cranks. Once there is compression in the #1 spark plug hole, proceed in the same manner.
9. After piston No. 1 is moved to TDC on the compression stroke, the TDC position for any of the other cylinders can be determined by turning the crankshaft 180°, following the firing order of the cylinders (refer to Specifications). For example, cranking the engine 180°after TDC for cylinder #1 brings the engine to TDC on the compression stroke for cylinder #3.