Tune-up specifications, 1968–1988

Plugs, gap, distributor, dwell angle, ignition timing, idle speed, CO, exhaust, engine codes and valve clearance for 63 model years across 16 models — the 911, 912, 914, 924, 928 and 944. Read from Porsche’s own workshop booklet and cited to the page. Extracted 11 September 2026.

Figures: 514
Model years: 63
Models: 16
Booklet pages read: 26 of 28

Read these against the booklet, not instead of it. This is OCR of a small-print pocket booklet, and a misread digit looks exactly like a real figure. Every row cites its page for that reason.

A blank is a blank, not a zero. Where the OCR could not read a figure cleanly it was thrown away rather than published, so gaps in these tables mean “go to the book”, never “the booklet said nothing”. Every figure shown had to match the shape its field takes — a timing has to read as degrees before or after top dead centre, an engine code as Porsche numbers them — which is what catches a plug code read as ebalS RNIOGY.

The booklet’s own contents page is the cross-check. Each page’s model years were checked against the contents list; a page that disagreed was not published. 4 year labels were misread by the OCR and taken from the contents page instead, and each of those records says what was read.

A pocket booklet for the workshop counter. It covers the cars as sold in the USA and Canada, which is why several pages are marked Canada and why the emission equipment is listed at all.

911

Model year	Fuel system	Secondary air pump	Throttle compensator	Ignition distributor vacuum unit	Diverter valve	Spark plugs	Spark plug gap	Ignition distributor	Dwell angle	Ignition timing	Idle RPM	CO %	Exhaust system	Engine code no.	Valve adjustment, cold (intake/exhaust)	Page
1968read as 1966	—	Yes	Yes	Yes	Yes	W250P21	0.35 mm	Bosch 0231.159.001	38° ± 3°	30° BTDC/6000	900 ± 50	—	Regular	901/14,901/17	0.1mm (.004 in.)	1
1969-T	—	No	Yes	No	No	W225T30	0.6 mm	—	40° ± 3°	35° BTDC/6000	900 ± 50	—	Regular	901/17,901/19	0.1mm (.004 in.)	1
1969-E	—	No	No	No	No	W265P21	0.55 mm	Bosch 0231.159.006	38° ± 3°	30° BTDC/6000	900 ± 50	—	Regular	901/09,901/11	0.1mm (.004 in.)	1
1969-Sread as 1969-5	—	No	No	—	No	W265P21	0.55 mm	—	38° ± 3°	30° BTDC/6000	900 ± 50	3.5 ± 0.5 at idle	Regular	907/10	O.1mm (.004 in. }	2
1970/71-T	—	No	No	—	No	W225T30	0.6 mm	—	49° ± 3°	35° BTDC/6000	900 ± 50	3.5705	Regular	—	Q.dmm (004 in.)	2
1970/71-E	—	No	No	—	No	W265P21	0.55 mm	—	—	30° BTDC/6000	900 ± 50	3.0 ± 0.5 atidle	Regular	911/01,911/04	QOdmm [.004 in.)	2
1970/71-S	—	No	No	—	No	—	0.55 mm	—	38° ± 3°	—	900 ± 50	3.0 ± 0.5 at idle	Regular	911/02	0.1mm (.004 in.)	3
1972-T	—	No	No	—	No	W265P21	0.6 mm	—	38° ± 3°	5° ATDC	900 ± 50	1.5-2.0 at idle	Regular	911/51,911/61	0.1mm: (.004-in.}	3
1972-E	—	No	No	—	No	W265P21	0.55 mm	—	—	5° ATDC	900 ± 50	2.0-2.5 at idle	Regular	911/52,911/62	0.1mm (.004 in.)	3
1972-S	—	No	No	Yes	No	W265P21	0.55 mm	—	—	5° ATDC	900 ± 50	2.0-2.5 at idle	Regular	—	0.4mm (.004 in.)	4
1973-T	—	No	—	Yes	No	W235P21	0.6 mm	Bosch	—	5° ATDC	900 ± 50	1.5-2.0	Regular	—	0.1mm (.004 in.)	4
1973-E	—	No	No	Yes	No	W265P21	0.55 mm	Bosch	—	5° ATDC	900 ± 50	2520.5	Regular	—	0.1mm (.004 in.)	4
1973-S	Bosch Mech. Fuel Inj.	No	No	—	No	W265P21	0.55 mm	Bosch	38° ± 3°	5° ATDC	900 ± 50	25-05	Regular	911/53	O.4mm (.004 in.)	5
1974	CIS Fuel Inj.	No	—	—	No	—	0.55 mm	Bosch	38° ± 3°	5° ATDC	900 ± 50	1.5 70.5	Regular	—	O.imm (.004 in.)	5
1974-S	CIS Fuel Inj.	No	—	—	No	W235P21	0.55 mm	Bosch	—	5° ATDC	900 ± 50	15705	Regular	—	0.1mm (004 in.)	5
1975	CIS Fuel Inj.	Yes	—	Yes	No	W295P21	0.55 mm	Bosch	38° ± 3°	5° ATDC	900 ± 50	—	49 States-Regular	—	0.1mm (.004 in.) \|	6
1976	CIS Fuel Inj.	Yes	—	Yes	No	—	0.55 mm	Bosch	36° ± 3°	5° ATDC	900 ± 50	—	49 States-Regular	—	0.1mm (.004 in.) ——————————	6
1977	CIS Fuel Inj.	Yes	—	—	No	W235P21	0.55 mm	Bosch	—	—	—	—	EGR, Thermo reactors	—	0.1mm {.004 in.) ———	6

911 SC

Model year	Throttle compensator	Ignition distributor vacuum unit	Diverter valve	Spark plugs	Spark plug gap	CO %	Exhaust system	Valve adjustment, cold (intake/exhaust)	Page
1978/79, SC	—	Yes	No	W145T30	0.8 mm	2521.0 sec. air disc.	CAT, EGR	O.4mm (.004 in.)	7
1980-SC	No	Yes	No	W225T30	0.8mm	0,4-0.8 oxygen sensor disc.	3 way CAT-	0.1mm (,004 in.)	7
1981/82/83-SC	No	Yes	No	—	0.8 mm	0.4-0.8 oxygen sensor disc.	3 way CAT-	Cimm (.004 in.)	7

911 Carrera

Model year	Fuel system	Secondary air pump	Diverter valve	Spark plug gap	Ignition distributor	Exhaust system	Engine code no.	Valve adjustment, cold (intake/exhaust)	Page
1984/85	AFC Fuel Inj.	No	No	0.7 ± 0.1 mm	Bosch 0237.505.001	3 way CAT-oxygen sensor	930/21	—	8
1986/87/88	AFC Fuel Inj.	No	No	—	Bosch 0237.505.001	3 way CAT-oxygen sensor	—	0.1m (.004 in.) wo	8

911 Turbo

Model year	Fuel system	Secondary air pump	Diverter valve	Spark plugs	Spark plug gap	Ignition distributor	Ignition timing	Idle RPM	Exhaust system	Engine code no.	Valve adjustment, cold (intake/exhaust)	Page
1976	CIS Fuel Inj.	Yes	Yes	P280P21	0.6 mm	Bosch	—	950 ± 50	—	930/51	0.1mm (.004 in.)	9
1977	CIS Fuel Inj.	Yes	Yes	P280P21	0.6 mm	Bosch	—	1000 ± 50	—	930/53	0.1mm (.004 in.)	9
1978/79	CIS Fuel Inj.	Yes	Yes	P280P21	0.6 mm	Bosch 0237.302.009	—	—	—	—	O.1mm (.004 in.)	9
1981/82 Canada	CIS Fuel Inj.	Yes	Yes	—	—	Bosch 0237.301.004	—	1000 ± 50	Regular	930/60	0.1mm (.004 in.) :	10
1983/84/85 Canadaread as 1983/64/85 Canada	CIS Fuel Inj.	Yes	Yes	W3DPO0	—	—	29° BTDC/4000	900 ± 50	Regular	930/66	O.imm (.004 in. OOO ll ee	10
1986/87/88	CIS Fuel Inj.	—	Yes	W3DPO	—	Bosch 0237.302.034	—	900 ± 50	3 way CAT	930/68	0.1mm (.004 in.) en ipneaseidl iy	10

912

Model year	Fuel system	Secondary air pump	Diverter valve	Spark plugs	Spark plug gap	Dwell angle	Ignition timing	Idle RPM	CO %	Exhaust system	Page
1968	Carb. Solex 40	—	—	W200T35	0.6-0.7 mm	50° ± 3°	3° BTDC	850 ± 50	3.5 sec. air disc.	Regular	11
1969	Carb. Solex	No	No	W200T35	0.6-0.7 mm	50° ± 3°	3° ATDC	900 ± 50	4.00.5	Regular	11
1976-E	AFC Fuel Inj.	Yes	No	W175M30	0.7 mm	47° ± 3°	27° BTDC/3500	—	0.5-1.2 sec. air disc.	Thermo reactors EGR	11

914/4

Model year	Fuel system	Secondary air pump	Ignition distributor vacuum unit	Diverter valve	Spark plugs	Spark plug gap	Ignition distributor	Idle RPM	CO %	Exhaust system	Page
1970	—	No	Yes	No	W175T2	0.6 mm	—	—	1.0-3.0	Regular	12
1971	—	No	Yes	No	W175T2	0.6 mm	—	—	1.0-3.0	Regular	12
1972	—	No	Yes	No	W175T2	—	—	—	1.0-3.0	Regular	12
1973 1.7 Ltr.	MPC Fuel Inj.	No	Yes	No	W175T2	0.6 mm	Bosch	850 ± 50	1,0-3.0	Regular	13
1973 2.0 Ltr.	MPC Fuel Inj.	No	Yes	No	—	0.6 mm	Bosch	900 ± 50	1:5	Regular	13
1974 1.8 Ltr.	AFC Fuel Inj.	No	Yes	No	W175T2	0.7 mm	Bosch	850 ± 50	2,0-3.0	Regular	13

914/6

Model year	Fuel system	Secondary air pump	Throttle compensator	Ignition distributor vacuum unit	Diverter valve	Spark plugs	Spark plug gap	CO %	Exhaust system	Page
1970/71	Weber Carb. 40IDTP13C	No	Yes	No	No	W230T30	0.6 mm	35205	Regular	15

924

Model year	Fuel system	Secondary air pump	Throttle compensator	Ignition distributor vacuum unit	Diverter valve	Spark plugs	Spark plug gap	Ignition distributor	Ignition timing	Idle RPM	CO %	Exhaust system	Page
1977	CIS Fuel Inj.	Yes	No	Yes	Yes	W200T30	—	Bosch	10° ATDC	—	49 states 1.57 0.5 Calif. 0.7, sec. air disc.	49-regular plus EGR Calif-CAT plus EGR	16
1977½read as 197712	CIS Fuel Inj.	—	No	—	—	W200T30	—	Bosch	3° ATDC	—	0.5-1.0 air pump disc.	CAT and EGR for all states	16
1978	CIS Fuel Inj.	—	—	Yes	—	W200T30	0.7 ± 0.1 mm	Bosch 0237.003.008	—	950 ± 50	49 states 0.5-0.1 Calif. 0.8-1.2 air	CAT and EGR for all states	16
1979	CIS Fuel Inj.	—	—	—	—	W200T30	—	—	—	950 ± 50	CA 0.8-1.2	ie and EGR for	17
1980	CIS Fuel Inj.	No	No	—	No	WR6DS	—	—	—	—	wire disconnected	CAT, oxygen sensor	17
1981	CIS Fuel Inj.	—	—	—	No	WR6DS	—	—	—	—	wire diconnected	CAT, oxygen sensor	17
1982	CIS Fuel Inj.	No	—	Yes	No	WR6DS	—	—	—	—	0.5-1.0 oxygen sensor wire disconnected	CAT, oxygen sensor	18

924S

Model year	Fuel system	Secondary air pump	Ignition distributor vacuum unit	Diverter valve	Exhaust system	Page
1987/88	AFC Fuel Inj.	No	No	No	3-way CAT oxy. sensor	19

924 Turbo

Model year	Fuel system	Secondary air pump	Throttle compensator	Diverter valve	Spark plug gap	Idle RPM	Page
1980	CIS Fuel Inj.	No	No	No	0.6 mm	900 ± 50	20
1981	CIS Fuel Inj.	No	No	No	0.7 mm	900	20
1982	CIS Fuel Inj.	No	No	No	—	900	20

928

Model year	Fuel system	Secondary air pump	Diverter valve	Spark plugs	Exhaust system	Page
1978/79	CIS Fuel Inj.	Yes	Yes	—	CAT. EGR	21
1980	AFC Fuel Inj.	No	No	WR8DS	CAT, oxy, sensor	21
1981	AFC Fuel Inj.	Yes	Yes	WR8DS5	CAT, oxy. sensor	21

928, 928S

Model year	Secondary air pump	Ignition distributor vacuum unit	Diverter valve	Spark plugs	Idle RPM	CO %	Page
1982	Yes	Yes	Yes	WR8DS	750 ± 50	0,6 * 0.2 oxy sensor disc.	22
1983/84	Yes	Yes	Yes	—	650 ± 50	0.6 ± 0.2 oxy sensor disc.	22
1985	Yes	No	Yes	WR7DC	—	0.6 * 0.2 oxy sensor disc.	22

928 S4

Model year	Fuel system	Secondary air pump	Ignition distributor vacuum unit	Diverter valve	Spark plugs	CO %	Exhaust system	Page
1987/88	LH-Jetronic Fuel Injection	Yes	No	Yes	WR7DC	0.4-1.2 oxy. sensor connected (not adjustable}	CAT, oxy. sensor	24

944

Model year	Fuel system	Secondary air pump	Throttle compensator	Diverter valve	Ignition distributor	Idle RPM	CO %	Exhaust system	Page
1983	AFC Fuel Inj.	—	No	No	Cap/Rotor only	900 ± 50	—	CAT, oxy. sensor.	25
1984	AFC Fuel Inj.	—	No	No	—	900 ± 50	—	CAT, oxy. sensor.	25
1985	AFC Fuel Inj.	—	No	No	Cap/Rotor only	—	—	CAT, oxy. sensor.	25
1986/87/88	AFC Fuel Inj.	No	—	—	Cap/Rotor only	—	0.4-0.8 measured before CAT. oxy. sensor. disc.	—	26

944S

Model year	Fuel system	Ignition distributor vacuum unit	Diverter valve	Ignition distributor	CO %	Exhaust system	Page
1987/88	AFC Fuel Inj.	No	No	Cap/Rotor only	0.4-1.2 oxygen sensor connected (Not adjustable)	CAT oxy. sensor	27

944 Turbo

Model year	Fuel system	Secondary air pump	Diverter valve	Exhaust system	Page
1986/87/88	AFC Fuel Inj.	No	No	3 way CAT, oxygen sensor	28

Source

Basic emission equipment and tune-up specifications, 1968–1988, Dr. Ing. h.c. F. Porsche AG. 28 pages. The scan places two booklet pages on one sheet, so each sheet was split and each booklet page OCR’d on its own; whole-sheet OCR interleaved the two tables. Model years are checked against the booklet’s own contents pages, transcribed by eye.

Only the specification tables are reproduced. Two of the 28 pages lost their model-year row entirely to the OCR and are not published at all, because without it there is no way to tell which column of figures belongs to which year.