
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

117-
4
CAMSHAFT
TIMING
CHAIN
15
.
Remove
mounting
bolts
from
left
and
right
camshaft
4
.
Insta¡¡
and
hand-tighten
sprocket
mounting
bolts
.
sprockets
.
16
.
On
M42
engines,
remove
upper
bolt
on
right
side
chainguide
and
unbolt
lower
timing
chainguide
below
crank-
shaft
.
17
.
Remove
camshaft
sprockets
from
camshafts
together
with
chain
and
crankshaft
sprocket
.
NoteWoodruffkey
when
removing
crankshaftsprocket
.
CA
UTION-
The
crankshaft
must
not
be
allowed
to
rotate
when
the
timing
chaín
is
removed
.
The
pistons
can
contact
the
valves
.
Camshaft
timing
chain,
installing
(4-cylinder
engines)
Inspectal¡
sprockets
for
wear
or
damage
.
Inspect
the
chain
guide
and
tensioner
rails
for
grooves
caused
by
chain
contact
.
Replace
any
partthat
is
worn
.
If
any
of
the
sprockets
are
worn,
the
chain
and
sprocketsare
replaced
asan
assembly
.
The
procedure
outlined
below
assumes
that
the
camshafts
and
the
crankshaft
arelocked
in
the
TDC
installation
positionwithspecial
tools
(shown
earlier
in
Fig
.
5
and
Fig
.
6)
.
1
.
Install
timing
chain
to
crankshaft
sprocket,
then
slide
sprocket
on
crankshaft
whílealigníng
woodruff
key
.
2
.
Place
camshaft
sprockets
on
chain,
then
place
sprock-
ets
oncamshafts
so
that
arrows
on
sprockets
point
up
and
elongatedholes
in
sprockets
are
centered
lo
tapped
holes
in
camshafts
.
See
Fig
.
9
.
.
I
Pa
-
s
~_
a
Ge
..
.
0012509
5
.
On
M42
engine
:
Install
lowerchainguide
.
6
.
On
M44
engine
:
Remove
allen-head
retaining
screw
at
left
chain-guide
.
Turn
slotted-head
of
adjusting
sleeve
so
that
sleeve
contacts
cylinder
head
.
Then
install
and
tighten'allen-head
screw
fully
.
See
Fig
.
10
.
Fig
.
10
.
Left
upper
chain
guide
adjusting
sleeve
(arrow)
.
Note
cam-
shaft
position
CAUTION-
Different
hydraulic
chaintensioners
were
used
duringmanufacture,
depending
onengíne
type
.
See
Fig
.
11
.
Note
that
the
late
style
tensioner
canbe
retrofitted
to
the
earlier
engíne,
so
be
sure
to
identify
the
versíon
of
tensioner
ínstalled
as
ínstal-
lation
instructions
vary
between
the
two
.
7
.
On
M42
engine
:
Disassemble
chain
tensioner
by
strik-
ing
outer
sleeve
against
a
solid
object
.
This
will
release
snap
ring
and
tensioner
will
separate
.
See
Fig
.
12
.
8
.
On
M42
engine
:
Clamp
chain
tensioner
piston
in
vice
(soft
jaws)
.
Slowly
compress
piston,
making
sure
de-
tent
ring
fits
into
taper
of
outer
sleeve
.
If
necessary,
press
ends
of
detent
ring
together
.
Slowly
continueFig
.
9
.
Camshaft
sprockets
correctly
installed
with
arrows
pointing
pressing
tensioner
together
until
snap
ring
audibly
upand
bores
centered
to
tapped
holes
(M44
engine)
.
clicks
into
outer
sleeve
.
Measure
overall
length
of
ten-
sionerto
confirm
correct
assembly
:
68
.5
mm
(2
.7
in
.)
.
3
.
On
M44
engine
:
Place
cylinder
position
sensor
plate
on
intake
camshaft
sprocket
so
that
arrowonsensor
plate
NOTE-
points
up
.
The
¡ate-style
tensioner
on
the
M44
engine
can
be
ret-rofittedto
the
M42
engíne
.
CAMSHAFT
TIMING
CHAIN,
4-CYLINDER

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

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

120-2
IGNITION
SYSTEM
Fig
.1
.
Ignition
characteristic
map
.
Disabling
Ignition
System
WARNING
-
The
ignition
system
is
a
high-energy
system
operat-
ing
in
a
dangerous
voltage
range
that
couldprove
to
be
fatal
if
exposed
terminals
or
live
parts
are
con-
tacted
.
Use
extreme
caution
when
working
on
a
car
with
the
ignition
on
or
the
engine
running
.
The
ignition
system
operates
in
a
lethal
voltage
range
and
should
therefore
be
disabied
any
time
senrice
or
repair
work
is
being
doneon
the
engine
that
requires
the
ignition
to
be
switched
on
.
The
engine
management
system
can
be
disabled
byremov-
ingthe
main
relay
.
The
relay
is
located
in
the
power
distribution
box
in
the
left
rear
of
the
engine
compartment
.
See
Fig
.
2
.
0013134
Fig
.
2
.
Maínsystem
relay
(arrow)
in
power
distribution
box
(left
rear
of
engine
compartment)
.
GENERAL
WARNING
-
"
Do
not
touch
or
disconnect
any
of
the
high
ten-
sion
cables
at
the
cotls
orspark
plugs
while
the
engine
ts
running
orbeingcranked
by
the
starter
.
Fatalvoltages
are
present
.
"
Before
operating
the
starter
without
starting
the
engine
(for
example
when
making
a
compression
test)
always
disable
the
ignition
.
CAUTION-
"
Prior
to
disconnecting
the
battery,
read
the
bat-tery
disconnection
cautions
gtven
at
the
front
of
thts
manual
on
page
viti
.
"
Do
not
attempt
to
disable
the
ignition
by
either
re-
moving
the
cotl
from
the
spark
plugs
(6-cylinder
engines)
or
disconnecting
the
coll
wires
from
the
plugs
(4-cylinder
engines)
.
"
Connect
or
disconnect
ignition
system
wires,
multiple
connectors,
and
ignition
test
equipment
leads
only
while
the
ignitionis
off
.
Switch
multtm-
eter
functions
or
measurement
ranges
onty
with
the
test
probes
disconnected
.
"
Do
not
disconnect
the
battery
while
the
engine
ts
running
.
"
Many
of
the
tests
of
ignition
system
components
require
the
use
of
high-impedance
test
equip-
ment
to
prevent
damage
to
the
electrical
compo-
nents
.
A
high
impedance
digital
multimeter
should
be
used
for
all
voltage
and
resistance
tests
.
AnLED
test
light
shouldbe
used
in
place
of
an
incandescent-type
test
lamp
.
"In
general,
make
test
connections
only
as
speci-fied
by
BMW,
as
described
inthis
manual,
or
as
described
by
the
instrumenta
manufacturer
.

IGNITION
SYSTEM
DIAGNOSTICS
IGNITION
SYSTEM
SERVICE
Poor
driveability
may
have
a
variety
of
causes
.
The
fault
On
4-cylinder
engines,
an
ignition
coil
pack
is
mounted
to
may
lie
with
the
ignition
system,
the
fuel
system,
parts
of
the
the
passenger
side
strut
tower
in
the
engine
compartment
.
emission
control
system,
or
a
combination
of
the
three
.
Be-
The
coil
pack
integrates
4
individual
coils
.
cause
of
these
interrelated
functions
and
their
effects
oneach
other,
it
is
often
difficult
to
know
where
to
begin
looking
for
On
6-cylinder
engines,
an
ignition
coil
is
located
directly
problems
.
above
each
spark
plug
.
For
this
reason,
effective
troubleshooting
should
alwaysbe-
gin
with
an
interrogation
of
the
On-Board
Diagnostic
(OBD)
system
.
The
OBD
system
detects
certain
emissions-related
engine
management
malfunctions
.
When
faults
are
detected,
the
OBD
system
stores
a
Diagnostic
Trouble
Code
(DTC)
in
the
system
ECM
.
In
addition,
the
Check
Enginewarning
light
will
come
on
if
an
emissions-related
fault
is
detected
.
Two
generations
of
OBD
areusedon
the
cars
coveredby
this
manual
.
See
100
Engine-General
for
OBD
information
.
On-Board
Diagnostics
"
1992-1995
models
............
...
.
..
...
OBD
I
"
1996
and
later
models
.........
.......
..
OBD
II
NOTE-
"
On
carswith
OBD
ti,
specialized
OBD
11
scan
tool
equipment
mustbeused
to
access
DTCs,
either
using
the
BMW
special
tool
or
a
`generic"
OBD
11
scan
tool
.
"
The
OBD
11
fault
memory
(including
an
illuminated
Check
Engine
light)
can
only
be
reset
using
the
spe-
cial
scan
tool
.
Removing
the
connector
from
the
ECM
or
dísconnecting
the
battery
will
not
erase
the
fault
memory
.
Basic
Troubleshooting
Principies
An
engine
that
starts
and
runs
indicates
the
ignition
system
is
fundamentally
working-delivering
voltage
toat
least
some
of
the
sparkplugs
.
A
hard-starting
or
poor-running
engine,
however,
may
indicate
ignition
coil
problems,
cracked
or
dete-
riorated
spark
plug
wires
(4-cylinder
engines
only),
and
worn
or
fouled
spark
plugs
.
WARNING
-
Inefficient
combustion
(richair/fuel
mixture)
can
cause
the
catalytic
converter
to
overheat
and
plug
.
An
overheated
catalytic
converter
can
also
bea
tire
hazard
.
Checking
for
Spark
IGNITION
SYSTEM
120-
3
WARNING
-
If
a
spark
test
is
done
incorrectly,
damage
to
theen-
gine
control
module
(ECM)
or
the
ignitioncoil(s)
may
result
.
Checking
for
spark
is
difficult
onengines
with
distributorless
ignition
systems
.
Try
Rmovng
the
plugs
and
inspecting
for
differences
be-
tween
them
.
A
poor-firing
plug
may
be
wet
with
fuel
and/or
black
and
sooty,
butnot
always
.
If
a
coil
is
not
operating,
the
engine
management
system
will
electrically
disable
the
fuel
injectorto
that
cylinder
.
The
key
is
to
look
for
differences
be-
tween
cylinders
.
Ignition
coil,
testing
and
replacing
(4-cylinder
engine)
1.
Disconnect
mainharness
connector
from
coils
:
"
On
M42
engine,
remove
plastic
covering
from
coils
and
disconnect
individual
harness
connectors
.
"
On
M44
engine,
disconnect
main
harness
connectorat
end
of
coil
pack
.
See
Fig
.
3
.
Fig
.
3
.
Ignition
coil
pack
for
M44
engine
(arrow)
.
Coil
harness
con-
nector
shown
at1
.
IGNITION
SYSTEM
SERVICE

GENERAL
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
.........
130-2
Intake
air
temperature
(IAT)
sensor,
Principles
of
Operatinn
.
.
.
.
.
.
.
.
.
.........
130-2
testing
and
replacing
...
.
...
.
.
.
.......
.
130-19
Basic
Engine
Settings
.
.
.
.
.
.
.
.
.
.
.
.
.
.
...
:
.
130-3
Throttle
position
sensor
(TPS),
DISA
(Dual
Resonance
Intake
System)
.
.
.
.
.
130-3
testing
and
replacing
...
.
...
.
.
.
.
.
...
.
.
.130-19
On-Board
Diagnostics
(OBD)
Idle
speed
control
valve,
testing
.
.
.
.
.
.
.
.
.
.
130-20
and
Fault
Diagnosis
.
.
....
.
......
.
.
.
...
130-4
Idle
speed
control
valve,
replacing
.
.
.
.
.
.
..
130-21
SecondaryAir
Injection
.
.
.....
.
.........
.
130-5
BOSCH
DME
M5
.2
COMPONENT
Warnings
and
Cautions
.
.
...
.
.
.
.........
.
130-6
REPLACEMENT
.....
.
......
.
....
.
.
.
..
130-21
ELECTRICAL
CHECKSAND
Mass
air
flow
sensor,
replacing
.
.
....
.
....
130-22
COMPONENT
TESTING
.
.
.
.
.
.
.
.
...
.
.
.
.
.
130-7
Engine
coolant
temperature
(ECT)
Main
sensor,
replacing
..
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
130-22
rela
y
testing
130
-7
,...
.
.
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
Intake
air
temperature
(IAT)
sensor,
Fuel
pump
relay,
testing
.
.
.
.
.
.
.
...
.
.
.
.
.
.
.
130-7
rep
lacin
.
.
.
.
.
.
.
.
.
.
.g
.
.
.
.
.
.
.
...
.
.
.
..
.130-22
Oxygen
sensor,
testing
(Boschsystems
only)
130-8
Throttle
poson
sensor
(TPS)
replacing
13022
,
..
.-
FUEL
DELIVERY
TESTS
...
.
....
.
.
.
...
.
130-9
Idle
speed
control
valve,
replacing
...
.
....
.130-23
Operating
fuel
pump
for
tests
.
.
.......
.
...
130-9
SIEMENS
MS
41
.1
COMPONENT
Relieving
fuel
pressure
and
REPLACEMENT
.
...
.
.
.
.
.
.......
.
....
.130-23
connecting
fuel
pressure
gauge
......
.
..
130-10
Residual
fuel
pressure,
testing
.
.....
.
.
.
.
.
130-10
Mass
air
flow
sensor,
replacing
.
.......
.
.
.130-25
Fuel
pressure
regulator
response
Engine
coolant
temperature
(ECT)
to
engine
load,
testing
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
130-11
sensor,
replacing
.....
.
.
.
.
.
.........
.130-25
Fuel
rail
and
injectors,
checking
...
.
.
.
.
.
.
.
130-11
Intake
air
temperature
(IAT)
sensor,
replacing
.
.
.
.
.
.....
.
.
.
.
.
.
.
.......
.
.
.130-25
Fuel
rail
and
injectors,
replacing
..
.
.
.
.
.
.
.
130-12
Throttleposition
sensor
(TPS),
replacing
.
.
.
130-26
Fuel
PressureRegulator
.........
.
.
.
.
.
.
.
130-13
Idle
s
eed
control
valve,
re
lacin
130-26
Fuel
pressure
regulatorreplacing
p
p
g
.'''...
.
'
,
(fuel
rail
mount)
...
.
.
.
.
.
.............
130-13
ECM
PIN
ASSIGNMENTS
.............
.
.
130-26
Fuel
pressure
regulator,
replacing
Engine
control
module
(ECM),
accessing
...
130-26
(undercar
mount)
.
.
.
.
.
.
.
.
.........
.
.
130-14
BOSCH
DME
M1
.7
COMPONENT
TESTS
AND
REPAIRS
.
.
.
.
.
...
.
.
.
.
.
.
.
.
130-14
Air
flow
sensor,
testing
and
replacing
.
.
.
.
.
.
130-14
Engine
coolant
temperature
(ECT)
sensor,
testing
and
replacing
...
.
.
.
.
.
.
.
.
130-15
Throttle
position
sensor
(TPS),
testing
and
replacing
.
..........
.
.....
130-16
Idle
speed
control
valve,
testing
and
replacing
.
.
.
.
.
............
130-16
BOSCH
DME
M3
.1
AND
M33
.1
COMPONENT
TESTS
AND
REPAIRS
.
.
.
130-17
Mass
Air
Flow
Sensor
.
.
.
.
.
.
.
.
.....
.
.
.
.
.130-17
Mass
air
flow
sensor
(hotwire),testing
and
replacing
.
.
.
.
.
.....
.
.
.
.
.
.
.
130-17
Mass
air
flow
sensor
(hot
film),
testíng
and
replacing
.
.
.
.....
.
.
.
.
.
.
.
.
.
130-18
Engine
coolant
temperature
(ECT)
sensor,
testing
and
replacing
..
.
.
.
.
.
...
.
130-18
130
Fuel
i
n
jection
FUEL
INJECTION
130-1
TABLES
a
.
Engine
Management
System
Variants
.........
.130-2
b
.
Mass
Air
Flow
Sensor
Variants
..
.
..
..........
.130-2
c
.
Fuel
Pressure
Specifications
..
.
.
...
..........
130-11
d
.
Engine
Coolant
Temperature
Sensor
or
Intake
Air
Temperature
Sensor
Test
Values
(DME
1
.7)
...
.
130-15
e
.
ThrottlePosition
Sensor
Tests
(DME
1
.7)
......
.130-16
f
.
Engine
Coolant
Temperature
Sensor
or
Intake
Air
Temperature
Sensor
Test
Values
(DME
3
.1/3
.3
.1)130-19
g
.
Throttle
Position
Sensor
Tests
(DME
3
.1/3.3
.1)
.
.130-20
h
.
ECM
Pin
Assignment-Bosch
DME
M1
.7
....
.
..
.130-28
i.
ECM
Pin
Assignment-Bosch
DME
M3
.1
.......
.130-30
j
.
ECM
Pin
Assignment-Bosch
DME
M3
.3
.1
.....
.130-32
k
.
ECM
Pin
Assignment-Bosch
DME
M5
.2
.......
.
130-34
I.
ECM
Pin
Assignment-Siemens
DME
MS
41
.1
..
.
130-36

FUEL
INJECTION
130-
3
Fuel
metering
.
The
ECM
meters
fuel
bychanging
the
The
engine
management
system
compensates
automatical-
opening
time
(pulsewidth)
of
the
fuel
injectors
.
To
ensure
that
ly
for
changes
in
the
engine
due
to
age,
minor
wear
or
small
injector
pulsewídth
is
the
only
factor
that
determines
fuel
me-
problems,
such
as
a
disconnected
vacuum
hose
.
Asa
result,
tering,fuel
pressure
is
maintained
bya
fuel
pressure
regula-
idle
speed
and
mixture
do
not
need
lo
be
adjustedas
partof
tor
.
The
injectors
are
mounted
lo
a
common
fuel
supply
called
routine
maintenance
.
the
fuel
rail
.
The
ECM
monitors
engine
speed
to
determine
the
duration
NOTE-
ofinjector
openings
.
Other
signals
to
the
ECM
help
determine
Poordriveabilitymaybe
encountered
when
the
batteryis
injector
pulse
time
for
different
operating
conditions
.
A
tem-
disconnected
and
reconnected
.
when
the
battery
is
dis-
connected,
the
adaptive
memory
is
lost
The
system
will
perature
sensor
signals
engine
temperature
for
mixture
adap-
readaptafterabout
ten
minutes
of
drfving
.
tion
.
A
throttle
position
sensor
signals
throttle
position
.
The
exhaust
oxygen
sensor(s)
signal
information
about
combus-
tion
efficiency
for
control
of
the
air-fuel
mixture
.
1992
to
1995
DISA
(Dual
Resonance
Intake
System)
engines
are
equipped
with
a
single
sensor
.
1996
and
later
(OBD
II)
engines
are
equipped
with
an
oxygen
sensor
before
TheE36
4-cylinder
engine
is
equipped
with
a
dual
intake
andone
after
each
catalytic
converter
.
Forexample,the
M52
runner
system,
termed
DISA
.
DISA
offers
the
advantages
of
engine
is
equipped
withfour
oxygen
sensors
.
both
short
and
long
intake
pipes
.
Long
intake
runners
are
most
useful
at
low
to
medium
engine
rpm
for
producing
good
Idle
speed
control
.
ldle
speed
is
electronically
controlled
torque
characteristics
.
Short
intake
runners
produce
hígherviathe
idle
speed
control
valve,
which
maintains
idle
speed
by
horsepower
at
hígher
engine
speeds
.
bypassing
varying
amounts
of
air
around
theclosed
throttle
valve
.
Idle
speed
is
not
adjustable
.
NOTE-
Knock
(detonation)
control
.
Knock
sensors
monitor
and
The
term
DISA
comes
from
the
German
words
Differen-
control
ignition
knock
through
the
ECM
.
The
knock
sensors
zierte
Sauganlage,
and
can
roughlybe
translated
as
"dif-
fering
intake
manifold
configuration
."
See
100
Engine-
function
like
microphones
and
are
able
to
convert
mechanical
General
foradditional
information
on
DISA
operation
.
vibration
(knock)
into
electrical
signals
.
The
ECM
is
pro-
grammed
to
react
to
frequencies
that
are
characteristic
of
en-
Manifold
construction
:
The
intake
manifold
is
a
two-piece
gine
knock
and
adapt
the
ignition
timing
point
accordingly
.
metal
construction,
with
a
pair
of
runners
in
thetop
section
See120
Ignition
System
for
further
details
.
and
four
runners
in
the
lower
section
.
A
butterfly
valve
is
in-
stalled
in
the
lower
section,
enabling
the
DISA
solenoid
toiso-
NOTE-
late
one
pair
of
runners
from
the
other
pair
.
See
Fig
.
2
.
The
1992
M50
engine
is
not
equipped
with
knock
sen-
Operation
.
With
the
DISA
butterfly
valve
closed,
the
pipes
sors
.
All
other
engines
are
equipped
with
two
knock
in
thetop
half
of
the
manifold
act
together
with
the
ram
air
sensors
.
pipes
in
the
lower
halfto
producea
single,
long
air
intake
pipe
for
each
cylinder
.
See
Fig
.
3
.
The
column
of
aír
oscíllating
in
Basic
Engine
Settings
this
combined
pipe
significantly
increases
engine
torque
in
the
medium
rpm
range
.
Idle
speed,
idle
mixture
(%CO),
and
ignition
timing
arenot
adjustable
.
The
adaptive
engine
management
system
is
de-
signed
to
automatically
compensate
for
changes
in
engine
op-
eratingconditions,
although
the
adaptive
range
is
limited
.
Once
these
limits
are
exceeded,
driveability
problems
usually
be-
come
noticeable
.
Above
approximately
4,800
rpm,
the
butterfly
valve
between
the
intake
air
pipes
for
the
two
cylinder
groups
is
opened
.
The
shorter
pipes
in
the
lower
manifold
section
now
become
the
main
suppliers
of
ram
air
to
the
cylinders,yielding
greater
pow-
er
at
the
upper
end
of
the
engine
rpm
range
.
See
Fig
.
4
.
Control
components
.
The
DISA
butterfly
valve
is
actuated
NOTE-
electro-pneumatically
via
the
engine
control
module
(ECM)
.
lf
the
system
adaptive
limits
are
exceeded,
the
Check
The
valve
begins
to
open
as
engine
speed
rises
aboye
4,840
Engine
light
will
most
likely
come
on,
indicating
an
rpmand
closes
below
4,760
rpm
.
The
action
of
the
valve
is
de-
emissions-
related
fault
For
Check
Engine
light
diag-
liberately
delayed
to
prevent
it
from
opening
and
closing
repeat-
nostics,
see100
Engine-General
.
edly
within
a
short
time
.
GENERAL