Disconnect the wiring harness and vacuum hose from the spark torque sensor. After unscrewing the fastening nuts, remove the spark moment sensor. Remove the fuel pump with gaskets, tappet and heat-insulating spacer, and then remove the accessory housing with the sealing ring.
Remove the cylinder head cover with gasket and rubber bushings. Remove the front toothed belt guard and turn the crankshaft clockwise until the mark on the camshaft pulley is against the alignment mark on the rear toothed belt cover (see fig. 20), and the mark on the flywheel was against the middle division of the scale (see fig. 67).
Loosen the axle nut 7 (see fig. 7) tension roller and turn it to a position in which the belt tension will be minimal. Remove the belt from the camshaft pulley. Holding the camshaft pulley from turning with tool 67.7811.9513, unscrew its fastening bolt and remove the pulley with the key. Instead of the named device, you can use some kind of lever with grips for the pulley holes.
Remove the cylinder head cover and camshaft bearing housing by unscrewing the fastening nuts. Remove the camshaft from the beds of the cylinder head and remove the oil seal from it.
Before installing the camshaft, check whether the locating sleeves of the camshaft bearing housings are in place (put on pins, see fig. 48). They clean the mating surfaces of the cylinder head and bearing housing from the remnants of the old gasket, dirt and oil.
Put a new oil seal on the camshaft, lubricating the end of the shaft with engine oil. Lubricate the bearing journals and camshaft cams with engine oil and place it together with the oil seal in the cylinder head bearings. Install the camshaft pulley with a key and turn it until the mark on the pulley aligns with the mark on the rear protective cover. The pulley bolt is not installed.
On the surface of the cylinder heads mating with the bearing housing, in the area of the extreme supports of the camshaft, a sealant of the SUPER THREE BOND No. 50 type or a similar sealant of domestic production of the KLT-75T type is applied (see fig. 48). It must be borne in mind that it is allowed to start the engine no earlier than 1 hour after applying the sealant. The exposure time of the sealant in air is allowed no more than 10-12 minutes.
Install the bearing housing and tighten the nuts of its fastening in two steps:
- 1st reception - pre-tighten the nuts in the sequence shown in fig. 21, until the surfaces of the bearing housing come into contact with the cylinder head, making sure that the mounting sleeves of the housing fit freely into their sockets;
- 2nd reception - finally tighten the nuts with a torque of 21.6 N·m in the same sequence.
Immediately after tightening the bearing housing fastening nuts, carefully remove the sealant residues squeezed out of the gaps during tightening in areas mating with the cylinder head cover gasket and with the auxiliary unit housing; non-removed cured sealant residues in these areas will cause oil to leak through the seals.
The threaded part of the camshaft pulley mounting bolt is degreased and UG-6 sealant is applied to it. Holding the camshaft pulley from turning with fixture 67.7811.9513, fix it with a bolt with a washer. When fixing the pulley, make sure that the mark on the pulley is approximately opposite the alignment mark on the rear toothed belt guard. The permissible mismatch is no more than 2 pulley teeth, otherwise the valves of the 2nd cylinder will rest against the piston. For this reason, it is also not allowed to turn and rotate the camshafts and crankshafts before installing the belt.
The position of the camshaft pulley is corrected until the mark on the pulley is exactly aligned with the mark on the rear protective cover and the belt is put on the pulley. Slightly tension the belt with the tension roller by turning the roller axis counterclockwise.
Turn the crankshaft two turns clockwise and check that the alignment marks on the camshaft pulley and the rear protective cover match, and also whether the mark on the flywheel is against the middle division of the scale (see fig. 67).
If the marks do not match, then loosen the belt with a tension roller, remove it from the camshaft pulley, correct the position of the pulley, put the belt back on the pulley and slightly tighten the tension roller. Again, check the coincidence of the installation marks by turning the crankshaft two turns.
If the alignment marks match, then adjust the belt tension, as indicated in Sec. «Engine adjustment», and gaps in the valve drive mechanism. Install the cylinder head cover with gasket and front toothed belt guard.
Install the accessory housing and fuel pump (see the description of the operation in sec. «Fuel pump»). Install the spark torque sensor so that the middle division of the scale on its body is against the mark on the body of auxiliary units. When installing the sensor, turn its roller in such a position that the cams of the roller clutch are against the asymmetric grooves of the camshaft. Attach wires and a vacuum hose to the spark moment sensor.
Install the air filter and attach the hoses of the crankcase ventilation system and warm air intake. Install the ignition coil, high voltage wires and windshield washer reservoir.
Connect the wire to the terminal «minus» battery, check and adjust the ignition timing (see sect. «Engine adjustment»). Install the spare wheel.