- Turn the crankshaft until the piston of the first cylinder is set to the TDC position. In this case, the mark on the pulley should coincide with the "0" mark on the scale on the casing cover.
- Check that the valve tappets of the first cylinder have a small play, and that the valve tappets of the fourth cylinder are under tension. If this is not the case, turn the crankshaft one more revolution.
- Measure the valve clearances according to Fig. 83 using feeler gauges inserted between the tappet and the cam surface. The clearances of the intake (E) and exhaust (A) valves on both engines are different and are given in the tables of dimensions and adjustments.
Fig. 83. Sequence of adjustment of valves indicated by arrows when setting the piston of the first cylinder to the TDC position E - intake camshaft; A - exhaust camshaft
- Rotate the engine one full revolution and measure the clearances shown in Figure 84.
Fig. 84. Adjust the valve clearances indicated by the arrows when setting the piston of the fourth cylinder to the TDC position E - intake camshaft; A - exhaust camshaft
- A sign of correct adjustment is that the end of the feeler gauge is inserted with resistance. To adjust the valve clearances, the adjusting washers should be replaced, but a special tool is required to remove and install the adjusting washers. To do this, turn the crankshaft until the appropriate cam is installed with the tip up and, using a special tool or otherwise, press the tappet so that you can pull out the adjusting washer with a small screwdriver. Before pressing the tappet, it should be turned so that the notch on top faces the spark plugs.
The adjusting washer can be calculated using the following formula:
- Measure the removed washer with a micrometer (Fig. 85) and record the result.
Fig. 85. Measuring the adjusting washer when adjusting valve clearances. The position of the adjusting washer relative to the tappet and camshaft is shown on the left
Calculate the thickness of the new washer to provide the required valve clearance. The following formula is used, but the engine type must be taken into account:
Engine 1.6 l (4A-F/FE)
Inlet valves:
- N = T + (A - 0.20 mm)
Exhaust valves:
- N = T + (A - 0.25 mm)
Engine 2.0 l (3S-FE)
Inlet valves:
- N = T + (A - 0.24 mm)
Exhaust valves:
- N = T + (A - 0.33 mm),
where "t" is the thickness of the removed washer, "A" is the measured valve clearance and "N" is the thickness of the new washer to be installed.
- Select the washer that is closest in thickness to the required clearance. There is a range of 17 washer sizes with thicknesses from 2.5 mm to 3.3 mm in 0.05 mm increments.
- To install the adjusting washer, press the pusher again and insert the washer.
- Measure the valve clearance as described above.
- Adjust the clearances of the remaining valves.
Do not allow the adjusting washer to fall into the engine. To avoid this, use a small screwdriver and a magnet, as shown in Figure 86. The washer should be pushed to the side and "caught" by the magnet.
Fig. 86. Removing the adjusting washer when adjusting valve clearances. Press the tappet with a special device (1) and remove the washer with a screwdriver (2) and a magnet (3)