Since 1978 model year the "230E" and "280E" models were equipped with a contactless TSZ ignition system with adjustment of the ignition advance angle by vacuum and centrifugal regulators of the ignition distributor sensor. The sensor is driven by an intermediate shaft.
The order of operation of the cylinders:
- M 115, M 102: 1-3-4-2
- M 110, M 123: 1—5—3—6—2—4
Battery
The battery is located in the front left part of the engine compartment. The negative terminal of the battery is connected to the car body.
Characteristic | Meaning |
Nominal voltage, V | 12 |
Nominal capacity, A.h | |
| 55 (Bosch 555.30: part numbers 0 093 055 530, 0 093 155 530 and 0 180 655 530) |
| 66 (Bosch 566.18: part numbers 0 093 056 618, 0 093 156 618 and 0 180 656 618) |
Ignition coil
Characteristic | Meaning |
Brand and type | Bosch K 12V (KW 12V), catalog numbers 0 221 119 030, 0 221 122 319 and 0 221 118 307/308 |
| Primary winding resistance, Ohm | 0.5-0.9 (or 2.9-3.4) |
| Secondary winding resistance, Ohm | 6,0—16,0 |
| Average power consumption at 1000 rpm⁻¹, W | 19—20 |
| Ignition voltage, kV | 14,0—16,0 |
The ignition coil is used with a primary winding resistance of 0.5-0.9 Ohm only with additional resistance of 0.9±0.005 Ohm.
Switch
Characteristic | Meaning |
Brand and catalog number (for TSZ system) | Bosch 0 227 100 114/115 |
Spark plugs
Characteristic | Meaning |
Brand and type | Bosch (Champion) |
| H7DC/H7DP (BN12Y); H8DC/H8DP (BN9Y) |
| W7DC/W7DP (N9Y) |
| W6DC/W6DP (N7Y, N7YC); W7DC/W5DP (N6Y, N6YC) |
| W7DC/W7DP (N9Y) |
| Gap between electrodes, mm | 0,8 |
Publication reprinted from this resource [Mercedesman.ru]
Ignition distributor data
Parameter, mm | Engine model | |||
M 115.938 | M 102.920, M 102.939 | M 102.980, M 102.982 | M 115.954 | |
| Catalogue No | 0.231.170.138, 0.227.100.920 | 0.237.002.084, 0.237.002.059 | 0.237.002.085, 0.237.002.066 | 0.231.170.138, 0.227.100.920 |
| Initial ignition advance angle (IAA) with vacuum hose disconnected, deg. (before TDC) | 14,0 | 10—16 | 10—16 | 14,0 |
| Setting the ignition timing with the vacuum hose disconnected, degrees (before TDC) / at crankshaft speed, rpm | 40/4500 | — | — | 40/4500 |
Control value of ignition timing | ||||
with vacuum hose disconnected, deg.: | ||||
| 10—18 | 10—16 | 10—16 | — |
| 13—19 | — | — | 13—19 |
| 30—36 | — | — | 30—36 |
with vacuum hose connected, deg.: | ||||
| — | — | — | — |
| 14—20 | — | — | +14—20 |
| ||||
Parameter, mm | M 123.920, M 123.921 | M 110.923 | M 110.984, M 110.988 | |
| Catalogue No | 0.231.187.004, 0.227.100.911 | 0.231.390.001, 0.227.100.914 | 0.237.302.002 | |
| Initial ignition advance angle (IAA) with vacuum hose disconnected, deg. (before TDC) | 5,0 | 10,0 | ||
| Setting the ignition timing with the vacuum hose disconnected, degrees (before TDC) / at crankshaft speed, rpm | 4032/4500 | 28/4500 | 32/3000 | |
Control value of ignition timing | ||||
with vacuum hose disconnected, deg.: | ||||
| — | — | — | |
| 13—20 | 11—17 | 16—20 | |
| 30—34 | 28 | 32 | |
with vacuum hose connected, deg.: | ||||
| from +4.0* | from +3.0 | from +3.0 | |
| +13—17 | +8—12 | +8—12 | |
| ||||
* 3 the "+" sign indicates that this value is given in degrees after TDC.
Tightening torques of the main threaded connections of the M 102 engine, kgf·m
Connection type | Meaning |
| Locknut of the valve drive thermal clearance adjusting screw | 2,0 |
Cylinder head mounting bolts | |
| 7,0 |
| turn 90° (m12 bolts with internal 12-sided socket head cap) |
| 2.5 (bolts M8) |
| Cylinder head cover mounting bolt | 1,5 |
| Camshaft Bearing Housing Fastening Bolt | 2,1 |
| Camshaft Sprocket Fastening Bolt | 8,0 |
| Timing chain tension compensation key | 0,5 |
| Chain tensioner plug | 7,0 |
| Chain tensioner housing | 1,0 |
Main bearing cap mounting bolts | |
| M12 | 9,0 |
M11 | |
| 5,5 |
| turn 95° |
M11x62 with internal 12-sided socket for key | |
| 5,5 |
| turn 90-100° |
Connecting rod cap bolt nut | |
| 4,0—5,0 (reusable bolts) or 5.0-6.0 (new bolts) |
| turn 90-100° |
| Camshaft Drive Cover Fastening Bolts | 2,3 |
| Oil pump cover mounting bolt | 1,0 |
| Oil pump pressure relief valve plug | 3,0 |
| Oil pan mounting bolt | 1,0 |
Oil pump oil receiver mounting bolt | |
| 2,3 |
| 1,0 |
| Oil drain plug | 3,0 |
| Water pump mounting bolt | 1,0 |
| Bolt for fastening pulley to water pump | 1,0 |
| Fan mounting bolt | 1,0 |
| Thermostat housing | 2,5 |
| Fuel pump mounting bolt | 2,5 |
| Distributor mounting bolt | 2,3 |
| Spark plugs | 1,5 |
| Engine suspension bracket mounting bolts | 4,0 |
| Bolts for fastening suspension brackets to the gearbox | 7,0 |
| Suspension bracket mounting bolts to cross beam | 2,0 |
| Powertrain travel limiter mounting bolt upwards to rear suspension bracket | 3,0 |
| Powertrain travel limiter adjustment bolt up | 13,0 |
| Shock absorber mounting bolt | 1,0 |
| Bolt securing the front buffer to the cylinder block | 2,5 |
| Bolt for fastening the pulley hub to the crankshaft | 30,0 |
| Bolt for fastening pulley to hub | 1,0 |
Flywheel mounting bolt | |
| 3,5 |
| turn 90-100° |
| Crankshaft rear oil seal retainer mounting bolt | 1,0 |
| Cylinder Block Drain Plug | 3,0 |
| Radiator drain plug | 1,5—2,0 |
Tightening torques of the main threaded connections of engines M 110, M 123, M 115, kgf·m
Connection type | Meaning |
| Camshaft gear | 8,0 |
| Connecting rod cap nuts | 4,1—5,0 |
Main Bearing Cap Bolts | |
| 8,0 |
| 9,0 |
| Crankshaft Front Flange Bolt: | |
| 40,0—45,0 |
| 27,0—33,0 |
| Flywheel mounting bolts | 3,0—4,1 |
| Intermediate disk | 5,0 |
| Body tray | 1,1 |
Oil filter housing | |
| 2,6 |
| 3,5 |
| Oil filter housing | 3,5—4,1 |
| Pressure reducing valve of the lubrication system | 4,1 |
Timing chain tensioner | |
| 8,9 |
| 5,0 |
| Camshaft housing (M 110) | 2,6 |
| Oil pan drain plug | 4,1 |
Valve cover | |
| 1,5 |
| 0,5 |
Cylinder head bolts | |
with hex head | |
| 4,1 |
| 7,1 |
| 11,0 |
with double hex head | |
| 4,0 |
| 7,0 |
| turn another 90° |
| turn another 90° |