Testing and adjusting firing point

Engine

Ignition distributor Bosch No.

Adjusting value¹) of firing point without vacuum 3500/min

Test value Ignition adjustment with/without vacuum

Vacuum adjustment in direction of

Installation value of ignition distributor at starting speed

without vacuum

Idle with

1500/min | 3000/min without

“retard” at idle

“advance”

at

3500/min

0 237 302 002

16-20°

110.984 110.985 110.986 110.987 110.994

0 237 302 003

OT±3°

-30¹

8-12¹

8-12¹

18-23^C

10

o before TDC

0 237 302 005 0 237 304 003 0 237 302 017 0 237 304 012

30

OT±3°

30^l

8-12″

8-12^L

110.988 110.989 110.990

0 237 306 045

20-24^

29-33^

10-14^L

12′

before

TDC

) If normally compressed engines are operated with fuel uder 98 RON (min. 88 MON), adjust firing point in direction of “retard” and match to octane rating of fuel used. The reference value for this adjustment is: set firing point back by 1—2 ° crank angle per 1 RON. Max. setback should not exceed 6 ° crank angle. Attention!

Taking firing point back is considered an “emergency measure”. Reduced output and increased fuel consumption will result. In addition, the engine should not be fully loaded. As soon as fuel with specified octane number is available, set again to full advance.

) To set firing point, pull off both vacuum lines for ignition adjustment. ³) Switch off air conditioner, automatic transmission in position “N” or “P”.

Ignition distributor Bosch No.

Adjusting value of firing point

with vacuum at idle

Test values Ignition adjustment

without vacuum

Vacuum adjustment in direction of

Installation value of ignition distributor at starting speed

without vacuum

“retard”

“advance”

at

3000/min

1500/min

3000/min

at idle

(aus) 1977

Identification: silver information plate on cross member in front of radiator.

0 237 302 002

TDC

25-35¹

8-12¹

10 before TDC

0 237 302 005 0 237 302 017

TDC

5-25^c

26-35″

8-12′

8-12′

10^u before TDC

0 237 304 018

2° after TDC

12—

25-31^u 3500/min

9-11′

8-12^l

10 before TDC

15.2 Mb—501/1 F2

Ignition distributor Bosch No.

Adjusting value of firing point

with vacuum at idle

Test values Ignition adjustment

without vacuum

Vacuum adjustment in direction of

Installation value of ignition distributor at starting speed

without vacuum

“retard’ at idle

“advance”

at

3000/min

1500/min

3000/min

(aus) 1982

0 237 304 021

2° after TDC

8-12′

19-23° 3500/min

9-1

8-12′

10 before TDC

(7) 1977/78/79

Identification: Information plate on cross member in front of radiator in Japanese language.

0 237 304 001

TDC

16-20

28-34^

8-12′

8-12

10 before TDC

0 237 304 003 0 237 304 010

TDC

15-25′

27-34^L

8-12′

8-12′

10 before TDC

1981

0 237 304 018

10° before TDC¹:

18-22¹

28-34′

9-1

8-12′

10 before TDC

0 237 304 021

10° before TDC¹)

8-12′

19-23^U 3500/min

9-1

8-12′

TDC

(T) 1977

Identification: Blue information plate in Swedish language on cross member in front of radiator.

0 237 302 002

TDC

14-19′

28-34′

8-12′

8-12′

10° before TDC

0 237 302 005

TDC

1 5-20

26-35^c

8-12′

8-12′

10^u before TDC

0 237 304 018

2 after TDC

12-18

25-31° 3500/min

9-1

8-12^C

10 before TDC

0 237 304 021

2 after TDC

8-12^c

19-23^U 3500/min

9-1 V

8-12′

TDC

15.2 llb-501/2 F2

Ignition distributor Bosch No.

Adjusting value of firing point

with vacuum at idle

Test values Ignition adjustment

without vacuum

Vacuum adjustment in direction of

Installation value of ignition distributor at starting speed

without vacuum

“retard” at idle

“advance”

at

3000/min

1500/min

3000/min

<usa> 1977

Identification: green/black information plate in English language on cross member in front of radiator

0 237 304 001

TDC

16-20^c

28-34¹

8-12′

8-12¹–

10^u before TDC

0 237 304 003

TDC

15-25^C

27-34¹

8-12^l

8-12¹

10^u before TDC

(usa) 1980

0 237 304 003

10° before TDC¹)

15-25^t

27-34″

8-12′

8-12¹

10^u before TDC

(usa) 1981

0 237 304 018

10° before TDC¹)

18-22¹

28-34^c

9-11

8-12¹

10 before TDC

) Adjusted with engine at operating temperature. Vacuum retard will be switched off above 50 °C engine temperature.

Digital tester

e. g. made by Bosch, MOT 001.03

Note

To improve emission values, standard engines are provided with a delay valve which is installed into vacuum line for vacuum advance.

When the throttle valve is quickly opened, the vacuum control unit will be activated with a vacuum under delay.

1 Delay valve

15.2 lib—501/3 F2

1    Test firing point with stroboscope or digital tester at specified speed and with or without vacuum.

2   Loosen ignition distributor fastening, if required, and set adjusting value of firing point by turning ignition distributor.

Screw down ignition distributor and check firing point once again.

3   Check centrifugal and vacuum adjustment of ignition distributor. For this purpose, run through specified test values with or without vacuum adjustment.

When testing vacuum advance, note that on engines with delay valve the vacuum will be established slightly slower.