1996 BMW 323i 130

116-2



CYLINDER
HEADAND
VALVETRAIN

3
.
Remove
timing
chain
sprockets
and
timing
chains
from



7
.
Slowly
release
pressure
oncamshaft
bearing
capsby
camshafts
.
Remove
upper
timing
chain
guidefrom
cyl-



turningeccentric
shaft
.
Remove
bearing
caps
and

inder
head
.
See117
Camshaft
Timing
Chain
.



camshaft
.
Repeat
procedureon
remaining
camshaft
.

NOTE-

It
is
not
necessary
lo
remove
the
lower
timing
chain
cover
.

4
.
Remove
spark
plugs
and
instaf
BMW
special
tool
11
3

260
to
cylinder
head
.
Tighten
tool
retaining
bolts
in

spark
plug
holes
.
Do
not
over-tighten
bolts
.
See
Fig
.
1
.

6
.
Remove
bearing
cap
mounting
nuts
.

0013033

5
.
Turn
eccentric
shaft
on
special
tool
until
pressure
is
ap-

plied
to
camshaft
bearing
caps
.
See
Fig
.
2
.

Fig
.
2
.



Special
tool
(eccentric
shaft)
being
turned
to
apply
pressure
to
camshaft
bearing
caps
.

CYLINDER
HEAD,
DISASSEMBLYAND
ASSEMBLY

CAUTION-

Camshaft
bearing
caps
mustbe
reinstalled
intheir
original
locations
.

NOTE-

"
The
camshaft
bearing
caps
are
coded
wíth
a
letter
anda
number
.
Forexample,
"Al
"ís
the
exhaust
cam-

shaft
bearing
cap
at
the
front
of
the
engíne,
and
"El"
is
the
intake
camshaft
bearing
cap
at
the
front
of
the
engine
.

"
Camshafts
are
stamped
with
a
code
letter-`E"
for
the
intakeside
and
`A"forthe
exhaust
side
.

"
"E"
isforEinlal3,
(German
for
íntake)
and
A"
isfor
Auspuff,
(German
for
exhaust)
.

"
The
front
of
the
engine
is
at
the
front
of
thecar
.

8
.
Camshaft
installation
is
reverse
of
removal,noting
the

following
:

"
Prior
to
installation,
check
al¡
components
for
wear
as

described
below
underCylinder
Head
and
Va¡-

Fig
.1
.



Special
BMW
tool
no
.
11
3
260
.
Tool
mounting
bolts
(arrows)



vetrain,
Reconditioning
.

thread
into
spark
plug
holes
.



"
Crankshaft
must
be
at
least
45°
away
from
TDC
before

installing
camshafts
to
cylinder
head
.

"
Lubricate
camshafts
prior
to
installation
.

Tightening
Torque



"
Install
camshafts
into
cylinder
head
with
lobes
for
cyl-

"
BMW
special
tool
11
1
260



inder
no
.
1
pointing
up
and
towards
each
other
.

to
cylinder
head
.
...
.
.
...........
23
Nm
(17
ft-Ib)



"
After
installing
camshafts),observe
specified
waiting

time
for
hydraulic
cam
followers
to
fully
compress
be-
fore
bringing
crankshaft
back
to
TDC
.

Camshaft
installation
waíting
times

"
Ator
above
68°F
(20°C)
............
.
..
10
minutes

"
50-68°F
(10-20°C)
................
..
.
30
minutes

"
32-50°F
(0-10°C)
.
.......
.
.........
..
.
75minutes
"
Reinstall
timing
chain
sprockets
and
tensioner
as
spe-

cifically
described
in
117
Camshaft
Timing
Chain
.



i

"
Wait
at
least
10minutes
before
cranking
engine
over

with
starter
motor
for
the
fi+



1
1/
/~~
.0
time
.

Tightening
Torques

"
Camshaft
bearing
caps

to
cylinder
head
(M7)
.............
15
Nm
(11
ft-Ib)

"
Cylinder
head
cover

to
cylinder
head
(M6)
.............
10
Nm
(89
in-lb)

"
Primary
timing
chain
tensioner
plug

to
cylinder
head
..
..
..
...........
40
Nm
(30
ft-Ib)

(see
117
Camshaft
Timing
Chain)

"
Spark
plugs
(M12)
..
.
.............
23
Nm
(17
ft-Ib

"
Timing
chain
cover
(upper)

to
cylinder
head
..
.
.
...
..........
10
Nm
(89
in-lb)

"
Timing
chainsprockets
to
camshaft

M6
........
.
...
.
..
.



..........
10
Nm
(7.5
ft-Ib)

M7



............
.
..
..
...........
15
Nm
(11
ft
.lb)

(see
117
Camshaft
Timing
Chain)

Camshafts,
removing
and
installing

(M44
engine)

Special
BMW
service
tools
should
always
be
used
to
remove

and
install
the
camshafts
.
Removal
and
installation
of
the
cam-

shafts
without
the
special
tools
can
result
in
camshaft
and
val-

vetrain
damage
.

1.
Disconnect
negative
(-)
battery
cable
.

CAUTION-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this

manual
on
page
vi¡¡
.

CYLINDER
HEAD
AND
VALVETRAIN



116-
3

2
.
Remove
spark
plugs
.
See
1201gnition
System
.

3
.
Rotateengine
until
a
pair
of
camshaft
lobes
are
point-
ing
up
.
Using
BMW
special
tool
115
130,
depresseach
valve
and
valve
spring
enough
to
remove
rocker
arms
.

Rotate
engine
for
the
next
pair
of
rocker
arms
.
See
Fig
.

3
.

cover
.

Fig
.
3
.



BMW
special
tool
no
.
11
5130
(arrow)
being
used
to
depress
valve
stem
to
remove
rocker
arm
.

WARNING
-

Removed
rocker
arms
must
be
reinstalled
in
the
same
locations
.

4
.
Remove
primary
timing
chain
tensioner
from
right
side

of
cylinder
head
.

The
camshafts
can
be
removed
with
the
cylinder
head



5
.
Remove
upper
timing
chaincover
.

mounted
onthe
engine
.
The
first
step
is
to
remove
the
cylinder

head
cover
.
See
113
Cylinder
HeadRemoval
and
Installa-



NOTE-

tion
.



lt
is
not
necessary
to
remove
the
lower
timing
chain

6
.
Remove
timing
chain
sprockets
with
timing
chains
from

front
of
camshafts
.
See
117
Camshaft
Timing
Chain
.

Remove
upper
timing
chain
guide
from
cylinder
head
.

WARNING-



7
.
Remove
camshaft
bearing
caes
and
remove
cam
The
process
of
evenly
loosening
the
camshaft
bear-



shafts
.
ing
cap
nuts
is
NOT
an
acceptable
method
of
re-

moving
the
camshafts
.
Be
sure
to
read
the



CAUTION-
procedure
through
before
starting
the
job
.
Camshaft
bearing
capsmust
be
reinstalled
intheir

original
locations
.

CYLINDER
HEAD,
DISASSEMBLYAND
ASSEMBLY

116-
8



CYLINDER
HEAD
AND
VALVETRAIN

0012502

Fig
.
10
.
Location
of
camshaft
oil
sprayer
tube
sea¡
in
M44
cylinder
head
(arrow)
.

Hydraulic
valve
adjusters,

checking
and
replacing
(M44
engine)

The
M44
engine
uses
hydraulic
valveadjusters
(HVA)
to
keep
valve
clearances
within
a
limited
working
range
.
See
Fig
.
11
.
HVAs
are
sealed
units
and
require
no
maintenance
.

1
.
Camshafts
2
.
Rocker
arms
3
.
Hydraulic
valve
adjusters
(HVA)
4
.
Valve
and
conical
valve
spring

Fig
.
11
.
Cutaway
view
of
M44
cylinder
head
.

Under
some
circumstances,
such
as
a
cold
start,
thehy-
draulic
units
may
become
noisy
.
Hydraulic
valve
adjusternoise
is
usually
ahigh-pitched
tapping
or
chattering
noise
.
In
most
instances,
this
is
consídered
normal
aslong
as
the
noise
goes
away
in
a
few
minutes
(maximum20
minutes)
.
If
thenoise
does
not
go
away,
either
the
hydraulic
unit
is
faulty
orthe
oil
pressure
tothe
adjuster(s)
is
low
.

CYLINDER
HEAD
AND
VALVETRAIN,
RECONDITIONING

NOTE-

8efore
checking
valveadjusters,
make
sure
engine
oil
is
fresh
and
at
proper
level
.

1
.
Run
engine
until
it
reaches
normal
operating
tempera-

ture
.

2
.
Turn
engine
off
and
remove
top
engine
cover,
spark

plugs,
and
cylinder
head
cover
.
See
113
Cylinder
Head
Removal
and
Installation
.

3
.
Use
a
plastic
or
wooden
stick
to
press
down
on
top
of

rocker
armend
(side
away
from
camshaft)
.
If
any
play
can
be
detected,the
HVA
is
faulty
and
should
be
re-

placed
.

NOTE-

When
checking
the
HVA,
make
sure
the
camshaft
lobe
is
facing
upso
that
there
is
no
valve
spring
pressure
on
the
adjuster
.

4
.
To
remove
an
HVA,
turn
engine
over
until
camshaft
lobe

points
straight
up
.
Using
BMW
special
tool
no
.
11
5
130,
depress
valvespring
and
remove
rocker
arm
from
under
camshaft
.
See
Fig
.
12
.

Fig
.
12
.
BMW
special
tool
no
.
115
130
(arrow)
being
used
to
depress
valve
stem
to
remove
rocker
arm
.

WARNING
-

Removed
rocker
armsmustbe
reinstalled
in
the
same
locations
.

Valves

Valve
specifications
are
listed
in
Table
d
.
Remove
carbon

deposits
from
thevalves
using
a
wire
brush
or
wire
wheel
.

Specification



M42
engine



M42IM44
engines



M50
engine



M50,
M52
engines



S50
USIS52
US
(1992)



(1993-1998)



(1992)



(1993-1998)



I
engine
(1995-1998)

Valve
head
dia
.
Intake



133
.0
mm
(1
.299
in)



133
.0
mm
(1
.299
in)



33
.0
mm
(1
.299
in)



33
.0
mm
(1
.299
in)



130
.0
mm
(1
.181
in)
Exhaust



30
.5
mm
(1
.201
in)



30
.5
mm
(1
.201
in)



30
.5
mm
(1
.201
in)



~
30
.5
mm
(1
.201
in)



27
.0
mm
(1
.063
in)

Valve
stem
dia
.
Standard
Intake



6
.975-0
.015
mm



5
.975-0
.015
mm



6
.975-0
.015
mm



5
.975-0
.015
mm



5
.975-0015
mm
(0
.2746-00006
in)



(0
.2352-00006
in)



(0
.2746-00006
in)



(0
.2352-00006
in)



(0
.2352
-
00006
in)
Exhaust



6
.960-0015
mm



5
.960-0
.015
mm



6
.960
--0
.015
mm



5
.960
-0
.015
mm



5
.960-0
.015
mm
(0
.2740-00006
in)



(0
.2345-0
.0006
in)



(0
.2740--0
.0006
in)



(0
.2345-0
.0006
in)



(0
.2345-0
.0006
in)

Intake



7
.075-0
.015
mm



6
.075-0
.015
mm



7
.075-0
.015
mm



6
.075-0
.015
mm



6
.075-0
.015
mm
(0
.2785-00006
in)



(0
.2392-0
.0006
in)



(0
.2785-00006
in)



(0
.2392
-
00006
in)



(0
.2392-00006
in)
Exhaust



7
.060-0015
mm



6
.060-0015
mm



7
.060-0
.015
mm



6
.060-0015
mm



6
.060-0015
mm
(0
.
2779-0
.0006
in)



(0
.2386-00006
in)



(0
.2779-00006
in)



(0
.2386-00006
in)



(0
.2386-00006
in)

Oversize
2
Intake



7
.175-0
.015
mm



6
.175-0
.015
mm



7
.175-0
.015
mm



6
.175-0
.015
mm



6
.175-0
.015
mm
(0
.2825-00006
in)



(0
.2431-00006
in)



(0
.2825-00006
in)



(0
.2431--0
.0006
in)



(0
.2431-00006
in)
Exhaust



7
.160-0015
mm



6
.160-0015
mm



7
.160-0
.015
mm



6
.160-0015
mm



6
.160-0-015
mm
(0
.2819
-
00006
i
n
)



(0
.2425-00006
in)



(0
.2819-00006
in)



(0
.2425-00006
in)



(0
.2425-00006
in)

Valves,
leak
test
NOTE-

BMW
speclal
tools
are
available
to
remove
the
valve
To
test
thevalves
for
leakage,
the
camshafts
and
camshaft



stem
oil
seals
.
As
an
alternative,
standard
valvesea¡

carriers
(where
applicable)
should
first
be
removed
.
Instali
the



removal
tools
are
available
from
most
automotive
parts

valve
assemblies
and
the
spark
plugs
in
each
cylinder
.
Place



stores
.
See
Flg
.
17
.

the
cylinder
head
on
a
workbench
with
the
combustion
cham-

ber
facing
upward
.
Fill
each
combustion
chamber
with
a
thin

non-flammable
liquid,
suchas
a
parts
cleaning
fluid
.
After
fif-

teenminutes,
check
the
leve¡
of
the
fluid
.
If
the
fluid
level
in
any

cylinder
drops,
thatcylinder
is
not
sealing
properly
.

Valve
Stem
Oil
Seals

The
purpose
of
the
valve
stem
oil
sea¡
is
to
prevent
excess

oil
from
entering
the
combustion
chamber
.
The
sign
offautty

valve
stem
oil
seals
is
excessive
oil
consumption
and
smoke

from
the
exhaust
immediately
after
starting
and
during
decel-

erat¡on

NOTE-

Valve
stem
oil
seals
should
not
be
reused
.
ff
valves
are

removed,
new
valve
stem
oil
seals
should
be
installed
.

Valve
stem
oil
sea¡
replacement
requires
that
the
cylinder

head
be
disassembled
and
thevalves
removed
as
described

above
under
Valves,
removing
and
installing
.

CYLINDER
HEAD
AND
VALVETRAIN



116-
11

Table
d
.
Valve
Specifications

Fig
.
17
.
Valve
stem
oil
sea¡
being
removed
from
valve
guide
.

Lubricate
the
new
seals
and
insta¡]
them
using
hand
pres-

sure
only
.
Be
sure
to
install
the
valve
spring
seat(s)
before
in-

stalling
the
sea¡
.

CYLINDER
HEAD
AND
VALVETRAIN,
RECONDITIONING

M42
Engine

CL
(EM

Fig
.
11
.
Two
versionsof
hydraulic
chaintensioners
.
Original
chain
ten-
sioner
on
M42
engine
(top)
canbe
disassembled
.
Chain
ten-
sioner
on
M44
engine
(bottom)
cannot
be
disassembled
.
Note
differences
in
outer
sleeve
.
Also,
the
M42
tensioner
de-
tent
ring
groove
is
visible
when
tensioner
is
extended
(arrow)
.

Outer
sleeve
Spring

0013024a

Detent

ring

9
.
On
M44
engines
:
Clamp
tensioner
piston
in
vice
(soft

jaws)
and
squeeze
oil
from
it
.
Slowly
compress
piston

only
up
to
end
círclip
.
Repeat
procedure
twice
to
ensure

al¡oil
is
expelled
.
See
Fig
.
13
.

10
.
Insta¡¡
hydraulic
chain
tensioner
lo
cylinder
head
.
Usea
new
sealing
washer
on
tensionerplug
when
installing
.

Tightening
Torque

"
Chain
tensioner
to
cylinder
head
....
40
Nm
(30
ft-Ib)

11
.
On
M42
engines
:
Release
early-style
chain
tensioner
by
pressing
chain
guide
against
tensioner
until
it
un-

locks
and
expands
out
.

CAMSHAFT
TIMING
CHAIN



117-
5

0012507

Fig
.
13
.
When
reinstalling
chain
tensiones,
oil
in
tensioner
piston
must

first
be
expelled
by
compressing
piston
in
vise
.
When
com-
pressing
piston,
only
compress
up
to
and
circlip
(arrow)
.

Tightening
Torque

"
Chain
sprocket
lo
camshaft
flange
(M6)
..
.
..
.............
.
..
10
Nm
(89
in-lb)

13
.
Remove
crankshaft
locking
tool
from
bellhousing
and

camshaft
locking
tool
from
rear
of
cylinder
head
.

14
.
Install
lower
timingchain
cover
:

"
Insta¡¡
new
crankshaft
oil
seal
in
cover
.

"
Use
new
gaskets
when
installing
cover
.

"
Thoroughly
clean
profile
gasketgroove
and
all
gasket

sealing
surfaces
on
lowerchaincover
.

"
Apply
a
small
bead
of
silicon
sealer
(3-Bond
1209
or
Snap



equivalent)
lo
joint
corners
where
chaincover
meets

ring



0013024



head
and
block
.
See
Fig
.
14
.

"
Tap
cover
into
position
to
engage
locating
dowels
.

Fig
.
12
.
Disassembled
early-style
chain
tensioner
usadon
M42
en-



"
Tighten
cover
mounting
bolts
alternately
and
in
stages
.

gine
.

12
.
Check
that
chain
is
now
free
of
siack
.
Tighten
down

sprocket
mounting
bolts
.



where
chain
cover
meets
head
and
block
(arrows)
.
Fig
.
14
.
Apply
sealer
(3-Bond
1209
0
or
equivalent)
to
joint
corners

CAMSHAFT
TIMING
CHAIN,
4-CYLINDER

117-
1
0



CAMSHAFT
TIMING
CHAIN

21
.
On
1993
and
lates
engines
:
Remove
access
plugs
from



24
.
On
1993
and
later
engines
:

VANOS
control
unit
in
front
of
exhaust
camshaft



"
Remove
VANOS
control
unit
as
described
laterinthis
sprocket
.
Remove
4
bolts
from
exhaust
camshaft



repair
group
.
sprocket
(useTono
El0
socket)
.
See
Fig
.
26
.



"
Remove
intake
camshaft
sprocket
mounting
nuts
.

"
Remove
intake
and
exhaust
sprockets
together
with

secondary
chain
.
Note
location
of
thrust
washers
and

spring
plate
(where
applicable)
on
intake
sprocket
.

Fig
.
26
.
Exhaust
camshaftmounting
bolts
(arrows)
.

CAMSHAFT
TIMING
CHAINS,
6-CYLINDER

0013056

22
.
Depress
secondary
timing
chain
tensiones
and
lock

down
by
inserting
stiff
wire
into
the
openings
in
rear
of
tensioner
.
See
Fig
.
27
.

Fig
.
27
.
Secondary
timing
chaintensioner
being
locked
down
on
M50
engine
.
Press
tensioner
downand
insert
locking
wire
through
holes(arrows)
.
Tensioner
on
M52/S52
US
engines
vary
slight-

23
.
Remove
secondary
chain
tensioner
and
lift
out
primary
chain
guide
.

NOTE-

Hold
the
camshaft
stationary
(at
hex
on
camshaft)
when
loosening
ortightening
sprocket
mounting
boits
.

CAUTION-

The
crankshaft
must
not
be
allowed
to
rotate
once
the
timing
chain
is
removed
.
The
pistons
can
con-
tact
the
valves
.

25
.
On
1992
engines
:

"
Remove
from
intake
and
exhaust
sprocket
mounting

bolts
.
"
Remove
sprockets
together
with
secondary
chain
.

26
.
Remove
bolts
holding
lower
timing
chain
cover
to
cylin-

der
head
(use
Torx
E8
socket)
.
See
Fig
.
28
.

MR111:
R

Fig
.
28
.
Cylinderhead-to-timingchain
covermounting
bolts
(arrows)
.

27
.
Using
a
drift,
drive
two
locatiog
dowels
in
left
and
right

sides
of
lower
timing
chaincover
toward
rear
of
car
.
Re-
move
covermounting
boits
and
carefully
lift
cover
off
.
See
Fig
.
29
.

CA
UTION-

Use
care
when
removing
the
cover
from
the
cylin-
der
head
gasket
.
If
the
cover
is
stuck,
useasharp
knife
to
separate
it
from
the
head
gasket
.

GENERAL
.
........
.
...........
.
.
.
.
.
.
.
120-1



Camshaft
Position
(CMP)
Sensor
....
.
.
.
...
120-6

Disabling
Ignition
System
.
.
.
.
.....
.
.
.
.
.
.
.
120-2



Camshaft
position
(CMP)
sensor,
replacing

Warnings
and
Cautions
.
.
.
.
.
.
.....
.
.
.
.
.
.
.
120-2



(4-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
...
120-6

Camshaft
position
(CMP)
sensor,
replacing

IGNITION
SYSTEM
DIAGNOSTICS
.
.
.
.
.
.
120-3



(6-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
120-7
Basic
Troubleshooting
Principles
...
.
.
.
.
.
.
.
120-3



Knock
sensors,
replacing
.
.
...
.
.
.
.
.
.
.
.
.
.
.
.
120-7

Ignition
Firing
Order
.....
.
...
.
.
.
.....
.
.
.
.120-7

IGNITION
SYSTEM
SERVICE
.
.........
.
120-3

Checking
for
Spark
..
.
.
.
.
.
.
.
.
.
.......
.
.
.
120-3

Ignition
coil,
testing
and
replacing

(4-cylinder
engine)
.
.
.
.
.
.
.
.
.
.
.........
.
120-3

Ignition
coil,
testing
and
replacing

(6-cylinder
engine)
.........
.
..........
120-4

Crankshaft
Positionlrpm
Sensor
.......
.
...
120-5

Crankshaft
position/rpm
sensor,
testing
and

replacing
(front
mounted)
.........
.
.
.
.
.
.
120-6

Crankshaft
position/rpm
sensor,replacing

(rear
mounted)
.....
.
.....
.
.....
.
.
.
.
.
.
120-6

GENERAL



Troubleshooting
and
testing
of
the
engine
management

system
should
be
carried
out
using
the
BMW
specialized
ser

This
repair
group
covers
repair
andcomponent
replace-



vice
tester
(scan
tool)
.

ment
information
for
the
ignition
system
.
All
engines
use
a
distributorless
ignition
system
with
indívid-

ual
ignitioncoils
for
each
cylinder
.
There
is
no
distributor
cap

NOTE-



or
ignition
rotor
.
Each
coil
can
be
selectively
controlled
by
the

"
Spark
plug
replacement
is
covered
in
020
Mainte-



engine
control
module
on
a
cylinder-by-cylinder
basis
.
On
later

nance
Program
.



systems,
knock
sensors
are
used
to
monitor
and
control
igni-

"
For
fuel
related
troubleshooting
and
testing,
see
130



tion
knock
(ping)
and
adjusttiming
accordingly
.

Fuel
lnjection
.
Ignition
timing
is
electronically
controlled
and
not
adjust-

All
engines
covered
by
this
manual
use
an
advanced
en-



able
.
The
engine
control
module
(ECM)
usesengine
load,
en-

gine
management
system
.
The
engine
management
system



gine
speed,
coolant
temperature,
and
intake
air
temperature

incorporates
on-board
diagnostics,
fuel
injection,
ignition
and



as
the
basic
inputs
for
timing
control
.
Knock
detection
is
also

other
advanced
engine
control
functions
.



an
input
to
the
control
module,
where
applicable
.

Table
a
.
Engine
Management
System
Variants

Engine
code



1
System

4-cylinder
M42
(1.8
I)



Bosch
DME
Ml
.7
M44
(1
.9
I)



Bosch
DME
M5
.2
(OBD
II)

6-cylinder
M50
1992
(2.5
I)



Bosch
DME
M8
.1
1993-1995
(2
.5
I)



Bosch
DME
M33
.1
M52
1996-1998
(2.8
I)



Siemens
MS
41
.1
(OBD
II)

1998
(2
.5
I)



Siemens
MS
41
.1
(013D
11)
S50US
(3.0
I)



Bosch
DME
M3
.3.1
S52US
(3.2
I)



Siemens
MS
41
.1
(OBD
II)

120
Ignition
System

IGNITION
SYSTEM



120-1

IGNITION
SYSTEM
SCHEMATICS
...
.
.
.
.120-7

TABLES

a
.
Engine
Management
System
Variants
......
120-1

b
.
Ignition
Coil
Resistance
(M42
engine)
......
120-4

c
.
Ignition
Coil
Resistance
(M44
engine)
......
120-4

d
.
Ignition
Coil
Resistance

(6-cylinder
engine)
..
.
.
.
.
.
.
.
.
.
.
.
.....
.
..
120-5

NOTE-

All
engines
coveredby
this
manual,
with
theexception

of
the
1992
M50,
incorporate
knocksensors
as
part
of

the
engine
management
system
.

The
initial
ignition
point
is
determined
by
the
crankshaft
po-

sition/rpm
sensor
during
cranking
.
Once
the
engine
is
run-

ning,
timing
is
continually
adjusted
based
on
operating

conditions
.
A
characteristic
ignition
map
is
shown
in
Fig
.
1
.
A

map
similar
to
the
one
shown
is
digitally
stored
in
the
engine

control
module
.

GENERAL

120-8



IGNITION
SYSTEM

1



1
.0
GN



1
.0
Gl
.0
GN
I



Ign
coil



1
.0
GN
.

Tti



%ti



r,



_%ti
_



_
ice_
I



25



52
5524



51



54



56
I



Power
input



power
input

t



U



Engine
Control
Module
(Bosch
DME
Ml
.7)



II



Powerinput
Mainrelaycontrol
I
15
42



43



16442868
67



34
6
26



27
1
-----



__
V



_



--



_

~
8K



.35
BK
.35
13,1
1



.35
YE



1



.35
BK35
VE
.35

3



cyl
.1

1

11

E

S
2

1
.0
BR

2
.5
BR

Ign
.
coil
cyl
.
3



II

Ign
.
coil



Ign
.
coil
3



cyI
.
2



1
Y
_
Y
2



k
3



cyl
.
4

IGNITION
SYSTEM
SCHEMATICS

Battery
voltage
in
run
or
start
(
vía
ignition
switchterminal
15)



WIRING
COLOR
CODE
4
.0
GN

1
.0
BR'V
.

Camshaft
Knock
Sensor
Knock
Sensor



Position
(cyl
.1-2)
(cyl
.3-4)



Sensor

Fig
.
13
.
Bosch
DME
M1
.7
ignition
system
circuit
for
M42
engine
.

Ground
(RH
rearof
engine
compartment,
rear
of
shock
tower)

N[INS

Crankshaftlrpm
Position
Sensor

Battery
voltage
in
run
or
start
(vía
main
relay
terminal
87)

Ground
(RH
rearof
engine
compartment,
rearof
shock
tower)

5GN

BK
-
BLACK
BR
"
BROWN
RD
-
RED
YL-
YELLOW
GN
-
GREEN
BL
-
BLUE
VI
-
VIOLET
GY
-
GREY
WT
-
WHITE
PK
-
PINK

Warning
:
Lethal
voltagepresent

Battery
voltage
at
all
times
to
Main
relay
(terminal
85)

'Y
Y

---------------------

0013087