1994 BMW 318i 800

B
-
1
ROBERT
BENTLEY,
INC
.
I
AUTOMOTIVE
PUBLISHERS

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tothis
manual
.
A
listing
of
updates
canbe
found
on
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web
Iat
www
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.com/update
s

Do
not
use
this
manual
unless
you
are
familiar
with
basic
automotive
repair
procedures
and
safe
workshop
practices
.
This
manual
illustrates
the
workshop
procedures
required
for
most
service
work
.
It
is
not
a
substitute
for
fui¡
and
up-to-dateinformation
from
the
vehicie
manufacturer
or
for
proper
training
asan
automotive
technician
.
Note
that
it
is
not
possible
for
us
to
anticipate
al¡
of
the
ways
or
conditions
under
which
vehicles
may
be
serviced
or
to
provide
cautions
as
to
all
of
the
possible
hazards
that
may
result
.

The
vehicie
manufacturer
will
continue
to
issue
service
information
updates
and
parts
retrofits
after
the
editorial
closing
of
this
manual
.
Some
of
those
updates
and
retrofits
will
apply
to
procedures
and
specifications
in
this
manual
.
We
regret
that
we
cannot
supply
updates
to
purchasers
of
this
manual
.

We
haveendeavored
to
ensure
the
accuracy
of
the
information
in
this
manual
.
Please
note,
however,
that
considering
thevast
quantity
and
the
complexity
of
the
service
information
involved,
we
cannot
warrant
the
accuracy
or
completeness
of
the
information
contained
in
this
manual
.

FORTHESE
REASONS,NEITHERTHEPUBLISHER
NORTHE
AUTHOR
MAKES
ANY
WARRANTIES,
EXPRESS
OR
IMPLIED,THATTHE
INFORMATION
IN
THIS
BOOK
IS
FREE
OF
ERRORS
OR
OMISSIONS,
AND
WE
EXPRESSLY
DISCLAIMTHE
IMPLIED
WARRANTIESOF
MERCHANTABILITY
AND
OF
FITNESS
FOR
A
PARTICULAR
PURPOSE,
EVEN
IF
THE
PUBLISHER
OR
AUTHOR
NAVEBEEN
ADVISED
OF
A
PARTICULAR
PURPOSE,
AND
EVEN
IF
A
PARTICULAR
PURPOSE
IS
INDICATED
IN
THE
MANUAL
.
THE
PUBLISHER
AND
AUTHOR
ALSO
DISCLAIM
ALL
LIABILITY
FOR
DIRECT,
INDIRECT,
INCIDENTAL
OR
CONSEQUENTIAL
DAMAGES
THAT
RESULT
FROM
ANYUSE
OF
THE
EXAMPLES,
INSTRUCTIONS
OR
OTHER
INFORMATION
IN
THIS
BOOK
.I
N
NO
EVENTSHALL
OUR
LIABILITY
WHETHER
INTORT,
CONTRACT
OR
OTHERWISE
EXCEEDTHECOST
OFTHIS
MANUAL
.

Your
common
sense
and
good
judgment
are
crucial
to
safe
and
successful
service
work
.
Read
procedures
through
before
starting
them
.
Thinkabout
whether
the
condition
of
your
car,
your
leve¡
of
mechanical
skill,
or
your
leve¡
of
reading
comprehension
might
result
in
or
contribute
in
some
way
to
an
occurrence
which
might
cause
you
injury,
damage
your
car,or
result
in
an
unsafe
repair
.
lf
you
have
doubts
for
these
or
other
reasons
about
your
ability
to
perform
safe
repair
workon
your
car,
have
the
work
done
at
an
authorized
BMW
dealeror
other
qualified
shop
.

Part
numbers
listed
inthis
manual
are
for
identification
purposes
only,
not
for
ordering
.
Always
check
with
your
authorized
BMW
dealer
toverifypart
numbers
and
availability
beforebeginning
service
work
that
may
requíre
new
parts
.

Before
attempting
any
work
on
your
BMW,
read
the
wamings
and
cautions
on
pages
vi¡
and
vi¡¡,
andany
waming
or
caution
that
accompanies
a
procedure
in
the
service
manual
.
Review
the
warnings
and
cautions
on
pages
vi¡
and
viü
each
time
you
prepare
to
workon
your
BMW
.

Special
tools
required
to
perform
certain
service
operations
are
identified
in
the
manual
and
are
recommended
for
use
.
Use
of
tools
other
than
those
recommended
inthis
service
manual
may
be
detrimental
to
the
car's
safe
operation
as
well
as
the
safety
of
the
person
servicing
thecar
.

Copies
of
this
manual
may
be
purchased
from
most
automotiveaccessories
and
parts
dealers
specializing
in
BMW
automobiles,
from
selected
booksellers,
or
directly
from
the
publisher
by
mail
.

The
publisher
encourages
comments
from
the
reader
of
this
manual
.
These
communications
havebeen
and
will
be
carefully
considered
in
the
preparation
of
this
and
other
manuals
.
Please
write
to
Robert
Bentley,
Inc
.,
Publishers
at
the
address
listed
on
the
top
of
this
page
.

This
manual
was
published
byRobert
Bentley,
Inc
.,
Publishers
.
BMW
has
not
reviewed
and
does
not
vouch
forthe
accuracy
of
thetechnical
specifications
and
procedures
described
in
this
manual
.

Libraryof
Congress
Cataloging-in-Publication
Data

BMW
3
SeriesService
ManualM3,
318i,
323i,3251,
328i,
Sedan,
Coupe
and
Convertible
:
1992,
1993,
1994,
1995,
1996,1997,
1998
.
p
.
c
m
.
Includes
index
.
ISBN
0-8376-0326-9
1
.
BMW
3
Series
automobile--Maintenance
and
repair--Handbooks,
manuals,
etc
.
I
.
Robert
Bentley,
inc
.
TL215
.13251356
1999
629
.28'
722--cic21



99-17179
CIP
Bentley
Stock
No
.
B398

Editorial
closing
01/99

0302010099
1098765432

The
paper
used
in
this
publication
is
acidfree
and
meets
the
requirements
of
the
National
Standard
for
Information
Sciences-
Permanence
of
Paper
for
PrintedLibrary
Materials
.
O

©Copyright
1999
Robert
Bentley,
Inc
.

All
rights
reserved
.
All
information
contained
in
this
manual
is
based
onthe
information
available
to
the
publisher
at
the
time
of
editorial
closing
.
The
right
is
reserved
to
make
changes
at
any
time
without
notice
.
No
partof
this
publication
may
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or
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orby
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.
This
includes
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and
tables
.
All
rights
reserved
underBerne
andPan-American
Copyright
conventions
.
Manufactured
in
the
UnitedStates
of
America

BMW
SERVICE
MANUUAS
BMW
7
Series
Service
Manual
:
1988-1994
7351,735iL,
740i,
740iL,
750iL
Robert
Bentley
ISBN
0-8376-0328-5

BMW
3
Series
Service
Manual
:
1992-1998
M3,
3181,323i,325i,
328i,
Sedan,
Coupe
and
Convertible
Robert
Bentley
ISBN
0-8376-0326-9
Glory
Days
:
When
Horsepowerand
BMW
Z3
Service
Manual
:
1996-1998



Passion
Ruled
Detroit
4-cylinder
and
6-cylinder
models



Jim
Wangers
ISBN
0-8376-0208-4
RobertBentley
ISBN
0-8376-0327-7



Alfa
Romeo
Owner's
BibleTM
BMW
3-Series
Service
Manual
:
1984-1990



Pat
Braden
with
foreword
by
Don
Black
3181,
325,325e(es),
325i(is),
and
325i



ISBN
0-8376-0707-9
Convertible
RobertBentley
ISBN
0-8376-0325-0



Ford
F-Series
Pickup
Owner's
BibleTM
Moses
Ludel
ISBN
0-8376-0152-5
BMW
5-Series
Service
Manual
:
1989-1995
5251,
530i,535i,
540i
including
Touring
Robert
Bentley
ISBN
0-8376-0319-6

BMW
5-Series
Service
Manual
:
1982-1988
528e,
5331,
535i,
535is
RobertBentley
ISBN
0-8376-0318-8

ENTHUSIAST
TITLES
Complete
Roundel
1969-1998
:30
Years
of
the
Magazine
of
the
BMW
Car
Club
of
America
(CD-ROM)
ISBN
0-8376-0322-6

A
French
Kiss
WithDeath
:
Steve
McQueen
and
the
Making
ofLe
Mans
Michael
Keyser
ISBN
0-8376-0234-3

The
Speed
Merchants
:
A
Journey
Through
The
World
of
Motor
Racing,1969-72Michael
Keyser
ISBN
0-8376-0232-7

Mustang
5
.0
Technical
Reference
&
Performance
Handbook
Al
Kirschenbaum
ISBN
0-8376-0210-6

Maximum
Boost
:
Designing,
Testing,
and
Installing
Turbocharger
Systems
Corky
Bell
ISBN
0-8376-0160-6

Volkswagen
Sport
Tuning
for
Street
and
Competition
Per
SchroederISBN
0-8376-0161-4

Sports
Carand
CompetitionDriving
Paul
Frérewithforewordby
PhilHill
ISBN
0-8376-0202-5

Automotive
Books
From
Robert
Bentley

GTI,
Golf,
and
Jetta
Service
Manual
:
1985-
The
Design
and
Tuning
of
Competition



1992
Gasoline,
Diesel,
and
Turbo
Diesel,
EnginesPhilipH
.
Smith,
6th
editionrevised
by



including
16V
Robert
Bentley
David
N
.
Wenner
ISBN
0-8376-0140-1



ISBN
0-8376-0342-0
Going
Faster
:
The
Skip
BarberRacing



Corrado
Official
Factory
Repair
Manual
:
School
Carl
Lopez
ISBN
0-8376-0227-0



1990-1994
Volkswagen
United
States
9M-f,
Ir-
Win
n
on
Alexander
with
foreword



ISBN
0-8376-0387-0

by
Mark
Martín
ISBN
0-8376-0070-7



Passat
Service
Manual
:
1990-1993,

The
Technique
of
Motor
Racing
Piero



including
Wagon
Volkswagen
United
States

Taruf
fi
with
foreword
by
Juan
Manuel
Fangio



ISBN
0-8376-0378-1

ISBN
0-8376-0228-9



Cabriolet
and
SciroccoService
Manual
:
Race
Car
Aerodynamics



1985-1993,
including
16V
Joseph
Katz
ISBN
0-8376-0142-8



RobertBentley
ISBN
0-8376-0362-5

The
Scientific
Design
of
Exhaust
and



VolkswagenFox
Service
Manual
:
1987-
Intake
Systems
Philip
H
.
Smith
and
John
C
.



1993,
including
GL,
GL
Sport
and
Wagon
Morrison
ISBN
0-8376-0309-9



RobertBentley
ISBN
0-8376-0363-3

Volkswagen
Model
Documentation



Rabbit,
Scirocco,
Jetta
Service
Manual
:
Joachim
Kuch
ISBN
0-8376-0078-2



1980-1984
Gasoline
Models,
including

Volkswagen
Beetle
:
Portrait
of
a
Legend



Pickup
Truck,
Convertible,
and
GTI
Robert

Edwin
Baaske
ISBN
0-8376-0162-2
Bentley
ISBN
0-8376-0183-5

Jeep
Owner's
BibleTM
Moses
Ludel
ISBN
0-8376-0154-1

Eurovan
Official
Factory
Repair
Manual
:



MANUUAS

Volkswagen
Inspection/Maintenance
(I/M)
Emission
Test
Handbook
:1980-1997
Volkswagen
of
America
ISBN
0-8376-0394-3

Rabbit,
Jetta
Service
Manual
:
1977-1984Diesel
Models,
including
Pickup
Truck
and
Turbo
Diesel
RobertBentley
ISBN
0-8376-0184-3

Super
Beetle,
Beetle
and
Karmann
Ghia
Official
Service
Manual
Type1
:1970-1979Volkswagen
United
States
ISBN
0-8376-0096-0

Beetle
and
Karmann
Ghia
Official
Service
Manual
Type1
:1966-1969
Volkswagen
United
States
ISBN
0-8376-0416-8
Harley-Davidson
Evolution
V
Twin
Owner's
BibleTM
Moses
Ludel
ISBN
0-8376-0146-0
Audi
100,
A6
Official
Factory
Repair
Manual
:
1992-1997,
including
S4,
S6,
quattro
and
Wagon
models
.
Toyota
Truck
&
Land
Cruiser
Owner's



Audi
of
America
.
ISBN
0-8376-0374-9
BibleTM
Moses
Ludel
ISBN
0-8376-0159-2



Audi
80,
90,
Coupe
Quattro
Official

AUDI
SERVICE
MANUUAS

The
Racing
Driver
Denis
Jenkinson



Factory
Repair
Manual
:
1988-1992
ISBN
0-8376-0201-7



including
80
Quattro,
90
Quattro
and
20-valve
models
Audi
of
America
Unbeatable
BMW
:
Eighty
Years
of



FUEL
INJECTION



ISBN
0-8376-0367-6
Engineering
and
Motorsport
Success



Ford
Fuel
Injection
and
Electronic
Engine



Audi
100,
200
Official
Factory
Repair
JeremyWalton
ISBN
0-8376-0206-8



Charles
O
Probst,
SAE



Manua1
:1988-1991
Audi
of
America
Control
:
1788-1993
.
BMW
6
Series
Enthusiast's
CompanionTM



ISBN
0-8376-0301-3



ISBN
0-8376-0372-2
Jeremy
W
.11

ISBN
0-8376-0149-5
Ford
Fuel
Injection
and
Electronic
Engine



Audi
50005
5000CS
Official
Fa
,ctory
BMW
Enthusiast's
CompanionTM
BMW



Control
:
1980-1987
Charles
O
.
Probst,
SAE



Repair
Manual
:
1984-1988
Gasoline,
Car
Club
of
America
ISBN
0-8376-0321-8



ISBN
0-8376-0302-1



Turbo,
and
Turbo
Diesel,
including
Wagon

BMW
Notecards
Series
1
Photography
by



Bosch
Fuel
In1ection
and
Engne



and
Quattro
Audi
of
America
ISBN
0-8376-
i
Klaus
Schnitzer
ISBN
0-8376-0211-4



Management
Charles
O
.
Probst,
SAE



0370-6

ISBN
0-8376-0300-5



Audi
5000,
50005
Official
Factory
Repair
Manual
:
1977-1983
Gasoline
and
Turbo
VOLKSWAGEN
OFFICIAL
SERVICE



Gasoline,
Diesel
and
Turbo
Diesel
MANUUAS



Audi
of
America
ISBN
0-8376-0352-8

New
Beetle
Service
Manual
:
1998-1999



Audi
40005,
4000CS,
and
Coupe
GT
RobertBentley
ISBN
0-8376-0385-4



Official
Factory
Repair
Manual
:
1984-1987including
Quattro
and
Quattro
Turbo
Audi
Jetta,
Golf,
GTI,
Cabrio
Service
Manual
:



of
America
ISBN
0-8376-0373-01993-early
1999,
including
VR6
and
TDI
Robert
Bentley
ISBN
0-8376-0366-8



SAAB
OFFICIALSERVICE

1992-1999
Volkswagen
of
America



Saab
90016
Valve
Official
Service
Manual
:
ISBN
0-8376-0335-8



19851993
RobertBentl



ISBN
0837603129
-ey---

Saab
900
8
Valve
Official
Service
Manual
:
1981-1988
Robert
Bentley
ISBN
0-8376-0310-2

Passat
Official
Factory
Repair
Manual
:



VOLVO
SERVICE
MANUAL
1995-1997
Volkswagen
of
America



Volve
240
Service
Manual
:
1983-1993
ISBN
0-8376-0380-3



Robert
Bentley
ISBN
0-8376-0285-8

Robert
Bentley
has
published
service
manualsand
automobile
books
since
1950
.
Please
write
Robert
Bentley,
Inc
.,
Publishers,
at
1734
Massachusetts
Avenue,Cambridge,
MA
02138,
visit
our
web
síte
athttp
://www
.rb
.com,
or
call
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for
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and
other
cars
.

010-
8



FUNDAMENTALSFORTHE
DO-ITYOURSELF
OWNER

TOOLS

Mostmaintenance
can
be
accomplished
with
a
small
selec-
tion
of
the
right
tools
.
Toolsrange
in
quality
from
inexpensive
junk,
which
may
brakk
at
first
use,
tovery
expensive
and
well-
made
tools
for
the
professional
.
The
best
tools
for
most
do-it
yourself
BMW
owners
He
somewhere
in
between
.



O

Many
reputable
tool
manufacturers
offer
good
quality,
mod-
erately
priced
tools
with
a
lifetime
guarantee
.
These
are
your
best
buy
.
They
cost
a
little
more,
but
they
are
good
quality
tools
that
will
dowhat
is
expected
of
them
.
Sears'
Craftsman®
line
is
one
such
source
of
good
quality
tools
.

Some
of
the
repairs
covered
in
this
manual
require
the
use
of
special
tools,
suchas
a
custom
puller
or
specialized
electrical
test
equipment
.
These
special
tools
are
called
out
in
the
text
andcan
be
purchased
through
an
authorized
BMW
dealer
.
As
an
alternative,
some
special
tools
mentioned
may
be
pur-
chased
from
the
following
tool
manufacturers
andlor
distribu-
tors
:

"
Assenmacher
Specialty
Tools
6440
Odell
Place,Boulder,
CO
80301
(303)
530-2424

"
Baum
Tools
Unlimited
.
Inc
.
PO
.
Box
87,
Longboat
Key,
FL
34228
(800)
848-6657

"
Schley
Products
Inc
.
5350
E
.
Hunter
Ave
.,
Anaheim
Hills,
CA
92807
(714)
693-7666

"
Zelenda
Machine
and
Tool
Corp
.
66-02
Austin
Street,
Forest
Hills,
NY
11375
(718)
896-2288

Basic
Tool
Requirements

The
basic
hand
tools
described
below
canbe
used
to
accom-
plish
most
of
thesimple
maintenance
and
repair
tasks
.

Fig
.
8
.



Types
of
wrench
heads
.
From
left,
open-end,
12-point
box-
Screwdrivers
.
The
common
fíat-blade
type
and
the
Phillips



end,6-point
box-end,
fiare
nut
.
type
will
handlealmost
all
screws
used
on
BMWs
.
Two
orthree
different
sizes
of
each
type
will
be
required,
since
a
screwdriver



The
cómbination
wrench
is
the
most
universal
.
It
hasone
of
the
wrong
size
will
damage
the
screw
head
.
See
Fig
.
7
.



open-end
andone
box-end
.
10mm
and
13mm
wrenches
arethe
most
common
sizes
needed
.
A
more
complete
set
of
A
complete
set
of
screwdrivers
should
also
include
Torx@



wrenches
would
inciude
6mm
through
19mm
sizes
.
typescrewdrivers
.

Wrenches
.
Wrenches
come
in
different
styles
for
different
uses
.
Fig
.
8
shows
several
.
The
basic
open-end
wrench
is
the
most
widely
used,
but
grips
on
only
two
sides
.
It
can
spread
apart
and
slip
off
more
easily
.
The
box-end
wrench
has
better
grip,
on
al¡
six
sides
of
a
nut
or
bolt
.

A
12-point
box-end
can
loosen
a
nut
or
bolt
where
there
is
less
room
for
movement,
while
a
6-point
box-end
provides
bet-
ter
grip
.
Forhex
fasteners
on
fluid
lines,
like
brake
lines
and
fuel
lines,
a
fiare-nut
wrench
offers
the
acivantages
of
a
box-end
wrench
with
a
slot
that
ailows
it
to
fit
over
the
line
.

TOOLS

B005FNG

Fig
.
7
.



Common
flat-blade
(top)
and
Phillips
(bottom)
screwdrivers
.
Offset
screwdríver
(right)
is
used
for
screws
with
limited
ac-
cess
.

B002FNG

Sockets
.
Socketsperform
the
same
job
asbox-end
wrench-
es,
but
offer
greater
flexibility
.
They
are
used
with
a
ratchet
han-
dle
for
speed
and
conveniente
and
can
be
combined
with
extensions
and
universal
joints
(swivels)
to
reach
fasteners
more
easily
.
Sockets
come
with
different
size
connections
to
drive
handies
or
extensions,
called
the
drive
size
.
The
most
common
drive
sizes
are
1
/4
in
.,
318
in
.,
and
1
/2
in
.

Sockets
come
in
6-point
and
12-point
styles
.
For
use
with
a
ratchet,
the
6-point
offers
a
better
grip
on
tight
nuts
and
bolts
.
6mm
to
19mm
sockets
arethe
most
needed
sizes
.
Below
is
a
list
oftypical
bolt
diameters
and
the
corresponding
wrench
siz-
es
.

camshaft
secondary
drive,
causing
thecamshaft
to
"advance"

12
.5°
.
The
helical
gears
are
cut
so
that
forward
motion
of
the

gear
cup
is
transiated
into
rotational
motion
of
the
camshaft
.

See
117
Camshaft
Timing
Chain
for
testing
and
repair
infor-
mation
on
the
VANOS
system
.

DISA
(Dual
Resonance
Intake
System)

DISA,usedon
4-cylinder
engines,
is
a
dual
intake
runner

system
that
effectively
provides
the
advantages
of
both
short

and
long
intake
runners
within
the
same
engine
.
For
best
per-

formance,
long
intake
runners
aremost
beneficial
atlow-
and
mid-engine
speeds
(below
4,200
rpm),
and
short
intake
run-
ners
enhance
torque
at
high
engine
speeds
(above4,200
rpm)
.

NOTE-

The
term
DISA
comes
from
the
German
words
Differ-
enzierte
Sauganlage,
and
can
roughty
be
transiated
as
a
differing
intake
manifold
configuration
.

The
DISA
solenoid
valve
is
controlled
by
the
DME
control

module,
using
engine
speed
as
the
primary
input
.
The
main

components
of
the
system
are
the
modified
twin-section
in-

takemanifoldwith
change-over
valve,
the
twin-barrel
throttle

body,
and
the
electrical/pneumatic
actuating
components
.

See
Fig
.
4
.

r

I

I

I

?
,
in
UpPer,
take
-1
manifold

1
-1
Throttle
housing
(Heated)

q
:lZU

Fig
.
4
.



DISA
system
components
.
DISA
changes
the
intake
runner

length
based
on
engine
speed
.

The
DISA
system
electro-pneumatically
changes
the
intake
runner
length
through
the
twin-section
intake
manifold
and
a
change-over
butterfly
valve
.
The
change-over
valve
is
located
at
a
point
in
the
intake
manifold
where
four
pipes
come
into
two
.
When
the
change-over
valve
is
closed,
the
4-way
primary
intake
manifold
and
the
2-way
ram
air
manifold
areconnected
to
make
the
"long"
configuration
.
When
the
change-overvalve
opens,
intake
air
flow
is
redirected
through
only
the
short
4-

way
primary
intake
manifold
.

The
change-over
valve
is
held
in
the
normally
open
position
bya
spring
.
Thisallows
for
an
open
valve
in
the
event
of
sys-
tem
failure
.
During
low
andmid
enginespeeds,
the
DME
con-

trol
module
supplies
power
to
the
solenoid
valve,
which
in
turn

allows
vacuum
to
be
applied
lo
the
vacuum
diaphragm
.
This

causes
the
valve
to
close
(long-pipe
configuration)
.
When
en-
gine
speed
reaches
approximately
4,800
rpm,
the
DME
con-
trol
module
electrically
signals
the
solenoid
valve
and
the
valve
opens,
creating
the
short
pipe
configuration
:

Further
detafs
on
DISA
canbefound
in
130
Fuel
Injection
.

Engine
Management
System

Al¡
enginescoveredby
this
manual
usean
advanced
engine

management
system
called
Digital
Motor
Electronics
(DME)
.

In
the
DME
system,
advancedOn-Board
Diagnostics
(OBD),

fuel
injection,
ignition,
and
otherfunctions,
are
combined
under

the
control
of
theEngine
Control
Module
(ECM)
.
See
Fig
.
5
.

-



Lower
intake
manifold

DISAvacuum
'
~servo

EíY1z

ENGINE-GENERAL
100-
3

le

-
DISA
solenoid
valve

0012591

/
with
butterfly
va¡

GENERAL

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