fuel sender BMW 318i 1992 E36 Workshop Manual

160
Fuel
Tank
and
Fuel
Pump

GENERAL
.
.
.
.
.
.
...........
.
....
.
.
.
.
.
.
160-1



Operating
fuel
pump
for
tests
.
.
.
.
.
.
.......
.160-6

Fuel
Pump
Electrical
Tests
.
.
.
.
.
.
.
...
.
.
.
.
.
160-7

FUEL
TANK
AND
LINES
..
.
.
.
..........
160-2



Fuel
pump
electrical
circuit,
testing.
...
.
.
.
.
.
160-7

Fuel
tank,
draining
..
.
.
.
.
.
.
.
.
.
..........
160-2



Fuel
pump
power
consumption,
testing
.
.
.
.
.
.
160-7

Fuel
tank,
removing
and
installing
.........
160-3



Fuel
Delivery
Tests
....
.
.
.
...
.
.....
.
.
.
..
160-8

Fuel
Tank
Evaporative
Control
System
.....
160-4



Relieving
fuel
pressure
and
connecting

fuel
pressure
gauge
..
.
...........
.
.
.
..
160-8

FUEL
LEVEL
SENDERS
.
.
.
.
.
.......
.
.
.
160-4



System
pressure,
testing
.................
160-9

Fuel
level
senders,
testing
.
.
.
.
.
.......
.
.
.
160-5



Fuel
delivery
volume,
testing
.............
160-10

Fuel
leve¡
sender
and
fuel
pump
(right
side),
emoving
and
installing
.
.
.
.
.
.
160-5



TABLES

Fuel
leve¡
sender
(left
side),



a
.
FuelLeve¡
Sender
Resistances
...........
.
.
..
.160-5

removing
and
installing
.........
.
.
.
.
.
.
.
160-6



b
.
Fuel
Pump
Current
...
.................
..
...
160-8

c
.
Fuel
Pressure
Specifications
..............
.
..
160-10

FUEL
PUMP
.
.
.
................
.
.
.
.
.
.
.
160-6



d
.
Fuel
Pump
Delivery
Specifications
.........
.
..
160-10

Fuel
Pump
Fuse
and
Relay
.
.
.
....
.
.
.
.
.
.
.
160-6

GENERAL

This
repair
group
covers
service
information
specifically
for



The
cautions
and
warnings
on
this
page
should
beob
the
fuel
supply
system
.
Information
on
the
fue¡
injection
sys-



served
when
servicing
the
fuel
system
.
tem
is
covered
in
130
Fuel
Injection
.

NOTE-

Fue¡
filter
replacement
is
covered
in
020
Maintenance
Program
.

WARNING
-

"
The
fuel
system
is
designed
to
retain
pressure
even
when
the
ignition
isoff
.
When
working
with
the
fuel
system,
loosen
the
fuel
lines
slowly
toal-
low
residual
fuel
pressure
to
dissipate
gradually
.
Avoid
spraying
fuel
.

"
Before
beginning
any
work
on
the
fuel
system,
place
a
tire
extinguisher
in
the
vicinity
of
the
work
area
.

"
Fuel
is
highly
flammable
.
When
working
around
fuel,
do
not
disconnect
any
wires
that
could
cause
electrical
sparks
.
Do
not
smoke
or
work
near
heaters
or
other
tire
hazards
.

"
Always
unscrew
the
fuel
tank
cap
to
release
pres-
sure
in
the
tank
before
working
on
the
tank
or
fines
.

"
Do
not
use
a
work
light
near
any
fuel
.
Fuel
may
spray
onto
the
hot
bulb
causing
a
tire
.

"
Make
sure
the
work
area
is
properly
ventifated
.

FUEL
TANK
AND
FUEL
PUMP



160-1

CAUTION-

"
Prior
to
disconnecting
the
battery,
read
the
bat-tery
disconnection
cautions
given
at
the
front
of
this
manual
onpage
viü
.

"
Before
making
any
electrical
tests
with
the
ignition
tumed
on,
disable
the
ignition
system
as
de-
scribed
in
120
Ignition
System
.
Be
sure
the
bat-tery
is
disconnected
when
replacing
components
.

"
To
prevent
damage
to
the
ignition
system
or
the
electronic
fuel
system
components,
including
the
control
unit,
aiways
connect
and
disconnect
wires
and
test
equipment
with
the
ignition
off
.

"
Cleanliness
is
essential
when
working
with
the
fuel
system
.
Thoroughly
clean
the
fuel
fine
unionsbefore
disconnecting
any
of
the
fines
.

"
Use
only
clean
tools
.
Keep
removed
parts
clean
and
sealed
or
covered
with
a
clean,
lint-free
cloth,
especially
if
completion
of
the
repair
is
delayed
.

"
Do
not
move
the
car
while
the
fuel
system
is
open
.

"
Avoid
using
high
pressure
compressed
air
to
blow
out
fines
and
componente
.
High
pressure
can
rupture
infernal
seals
and
gaskets
.

"
Always
replace
seals
and
O-rings
.

GENERAL

160-2



FUEL
TANK
AND
FUEL
PUMP

0011943
1
.
Filler
pipe



10
.
Fuel
compensating
siphon
pump
and
hose
assembly
2
.
Filler
pipe
grounding
tab



(models
built
from
1/95)
3
.
Vent
pipe



11
.
Fueltank
4
.
Threaded
collar



12
.
Tank
support
strap
5
.
Rubber
ring
seal



13
.
Bolt-tighten
to
23
Nm
(17
ft-Ib)
6
.
Fuel
pump



14
.
Fuel
expansion
tank
7
.
Left
side
fuel
leve¡
sender(models
built
from
1/95)



15
.
Fuel
tank
pressure
sensor
(OBD
II)
8
.
Right
side
fuel
leve¡
sender9
.
Left
side
fuel
leve¡
sender
with
fuel
compensating
siphon
pump
(models
built
up
to
1/95)

Fig
.
1
.



E36
fuel
tank
assembly
.

FUEL
TANK
AND
LINES



Fuel
tank,
draining

The
plastic
fuel
tank
is
mounted
beneath
the
center
of
the
car
(beneath
rear
seat)
.
Mounted
in
the
fuel
tank
are
the
fuel
pump
and
fuel
leve¡
sending
units
.
Connecting
lines
for
the
evaporative
emission
control
systemand
expansion
tank
are
also
attached
to
the
tank
.
When
performing
the
procedures
that
follow,
refer
toFig
.
1
.

Fuel
tank
capacity
for
E36
modeis

"All
ex
.
1996
M3
(3
.0
L)
.....
.
..
..
65
liters
(17
.0
gal)

"
1996
M3
(3.0L)
modeis
.
...
.
..
.
.62
liters
(16
.4
gal)

FUEL
TA
NKAND
LINES

The
fuel
tank
should
be
drained
into
an
approved
storage
unit
or
another
car's
fuel
tank
.

WARNING
-
"
Before
removing
the
tank,
be
sure
that
afl
hot
components
such
as
the
exhaust
system,
are
completely
cooled
down
.

"
Fuel
may
be
spilled
.
Do
not
smoke
or
worknear
heaters
or
other
Pire
hazards
.

1
.
Disconnect
negative
(-)
cable
from
battery
.

CAUTION-

Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
on
paga
vi¡¡
.

2
.
Remove
fuel
tank
filler
cap
.

3
.
Remove
rearseat
cushion
and
pull
back
insulation
mats
to
expose
fuel
tank
access
covers
.
See
Fig
.
2
.

uui3140

Fig
.
2
.



Right
side
fuel
tank
access
cover
under
rear
seat
cushion
.

4
.
Remove
right
and
left
access
covers
to
expose
fuel
hoses
and
electrical
connections
at
tank
.

5
.
Label
fuel
hoses
.
Then
disconnect
hoses
and
harness
connectors
from
fuel
sending
units
and
fuel
pump
.
See
Fig
.
3
.

FUELTANK
AND
FUEL
PUMP



160-
3

NOTE-

"
If
necessary,
push
fuel
level
sender
arm
toward
fuel
pump
assembly
to
facilitate
removal
.

"
BMW
special
tool
no
.
16
1
020
should
beused
tore-
move
and
install
the
threaded
collar
.
Damage
to
thecollar
may
result
if
the
special
tool
is
not
used
.

"
Pump
out
contents
of
each
tanklobe
using
approved
pumpinglextraction
equipment
and
flexible
fuel-grade
hose
.

WARNING
-

Fuel
may
be
spilled
.
Do
not
smoke
or
work
near
heaters
or
other
fire
hazards
.

7
.
Installation
of
sending
units
is
reverse
of
removal,
not-
ing
the
following
:

"
Use
new
sealing
rings
when
installing
pump/sending
unit
assemblies
.
"
Be
sure
that
fuel
line
connections
point
in
same
direc-tion
as
they
carne
out
.
"
Fill
tank
and
check
for
leaks
by
running
engine
.

CA
UTION-

Before
starting
the
engine,
fill
the
fuel
tank
with
at
least
1.5
gallons
(5liters)
of
fuel
.
The
pump
will
be
damaged
if
you
run
it
without
fuel
.

Fuel
tank,
removing
and
installing

1.
Disconnect
negative
(-)cablefrom
battery
:

CAUTION-

Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautions
given
at
the
front
of
this
manual
onpage
viii
.

2
.
Remove
fuel
tank
filler
capand
drain
tank
as
described
earlier
.

3
.
Working
in
left
access
tank
access
hole
(under
rear

seat
cushion),
remove
vent
pipe
fromtank
.

4
.
Working
inside
car,
disconnectparking
brake
cable
ends
from
parking
brake
lever
.
See
340
Brakes
.

5
.
Working
underneath
car,
gently
pry
fuel
lines
away
from
retaining
bracket
in
front
of
tank
.
Remove
clamps
and
disconnect
fuel
hoses
as
shown
in
Fig
.
4
.

6
.
Remove
exhaust
system
and
heat
shield
as
described

ooisiai



in
180
Exhaust
System
.
See
Fig
.
5
.

Fig
.
3
.



Fuel
pump/fuel
level
sender
assembly
in
top
offuel
tank
(right
side
shown)
.
Disconnect
supply
hose
(A),
return
hose
(B)
and



7
.
Remove
driveshaft
.
See
260
Driveshaft
.
harness
connector
(C)
.

8
.
Pull
parking
brake
cables
backward
away
from
bottom
of

6
.
Unscrew
threaded
collars
from
fuel
tank
.
Slowly
with-



fuel
tank,
disengaging
them
from
brackets
as
needed
.

draw
fuel
sender
assemblies
from
tank,allowing
fuel
to
drain
off
.

FUEL
TANKAND
LINES

160-
4



FUEL
TANK
AND
FUEL
PUMP

Fig
.
4
.



Pinch
off
supply
and
retum
fuel
hoses
(arrows)
before
dis-
connecting
from
rigid
metal
lines
.

0013143

Fig
.
5
.
After
removing
exhaustsystem,
remove
heat
shield
screws
(arrows)
and
heat
shield
.

9
.
Working
underneath
car,
loosen
hose
clamp
and
dis-

connect
filler
hose
.

10
.
Support
tank
from
below
.
Remove
tank
strap
mounting

bolts
.
Lower
and
remove
tank,
disconnecting
right
side



TheE36
model
uses
a
two-lobed
fuel
tank
and
each
lobeof
vent
and
other
hoses/electrical
connectors
as
neces-



the
tank
has
its
own
fuel
level
sending
unit
.
sary
.

11
.
Installation
is
reverse
of
removal
.

"
Always
use
new
seals,
gaskets,
O-rings,
and
hose
clamps
.

"
Inspect
hoses
and
replace
any
that
are
chafed,
dried

outor
cracked
.

"
Inspect
heat
shield
and
replace
if
corroded
.

"
Inspect
rubber
buffers
and
liners
on
fuel
tank,
support
straps
and
on
underside
of
body
.
Replace
rubber

parts
that
are
hardened
or
damaged
.

FUEL
LEVEL
SENDERS

CAUTION-

"
Before
starting
the
engine,
fill
the
fuel
tank
with
at
least
1.5
gallons
(5
liters)
of
fuel
to
prevent

damaging
a
dry
fuel
pump
.

"
If
the
filler
neck
has
been
removed
from
the
body,
be
sure
toreattach
theneck's
grounding
screw
(where
applicable)
.
Check
electrical
resistance
between
the
ground
tab
and
wheel
hub
.
The
re-
sistance
shouldbeno
higher
than
0
.6
ohms
.

Tightening
Torques

"
Fuel
tank
to
body
.............
...
23
Nm
(17
ft-Ib)

"
Hose
clamps
(10
mm-16
mm
día
.)
..
2
.0
Nm
(18
in-lb)

Fuel
Tank
Evaporative
Control
System

The
fuel
tank
evaporative
control
system
is
used
to
vent
the

fuel
tank
to
a
charcoal
canister,
which
is
then
purgedby
en-

gine
vacuum
during
normal
engine
operatíon
.
This
controls

emission
of
raw
hydrocarbons
(fuel)
to
the
atmosphere
.
See

Fig
.
1
.

A
fuel
expansion
tank,
located
under
the
right
rear
fender,

traps
overflow
fuel
and
incorporates
extra
fuel
tank
plumbing
.

Startingwith
1996
models,
OBD
II
standards
require
that

the
fuel
tank
evaporative
control
system
be
monitored
for

leaks
.
This
is
accomplished
usingthe
fuel
tankpressuresen-

sor,
the
ventshut
off
valve,
and
the
evaporative
purge
valve
.

NOTE-

On
most
early
cars(1992-1995),
the
charcoal
canister

is
in
the
engine
compartment
.
On
latercars,
the
char-
coal
canister
is
under
the
spare
tire
in
the
luggage
com-
partment
.

FUEL
LEVEL
SENDERS

The
right
side
fuel
leve¡
sender
is
integrated
with
the
fuel

pump
.
Each
senderhas
a
float
connected
to
a
variable
resis-

tance
for
fuel
leve¡
.
When
replacing
the
sender/pump
assem-

bly
always
replace
hose
clamps,gaskets
and
O-rings
.

WARNING
-

When
removing
the
fuel
level
sender
or
the
fuel
pump,
the
fuel
tank
should
be
emptied
.

Fuel
leve¡
senders,
testing



Fuel
leve¡
sender
(right
side)

The
left
and
right
fuelleve¡
sending
units
are
wired
in
series
.



and
fuel
pump,
removing
and
installing

The
fuel
gauge
receives
a
signal
that
is
the
average
of
the
two



1
.
Disconnect
negative
(-)
cable
from
battery
.

input
values
.

1
.
Remove
rear
seat
cushion,
lift
up
insulation
mats,
andremove
both
fuel
tank
access
covers
.

2
.
Disconnect
white
plug
on
each
sending
unit
.
See
Fig
.
6
.

3
.
Check
resistance
value
of
eachsending
unit
.
Values
should
be
the
same
.

5
.
If
valuesare
different,
remove
sending
units
as
described

below,
and
check
resistance
valuésacross
terminals
.
Table
a

lists
resistance
values
for
senders
at
various
float
positions
.

Table
a
.
Fuel
Leve¡
Sender
Resistances

Float
position



Test
result
(ohms)

Right
side
empty



10
ohm
t2

Right
side
full



250
ohm
±
5
Left
side
empty



10
ohm
t
2

Left
side
fui¡



250
ohm
±
5

FUEL
TANK
AND
FUEL
PUMP



160-
5

CAUTION
-

Prior
to
disconnecting
the
battery,
read
the
battery
disconnection
cautionsglven
at
the
front
of
this
manual
onpage
viii
.

2
.
Drain
fuel
from
tank
as
described
earlier
.

WARNING
-

Always
unscrew
the
fuel
tank
cap
to
release
pres-
sure
in
the
tank
before
working
on
the
tank
or
fines
.

3
.
Remove
rear
seat
cushion
and
pull
back
insulation
pad
under
right
side
.

4
.
Remove
screws
holding
rightfuel
tank
accesscover
.

Remove
cover
.

5
.
Label
fuel
hoses
.
Disconnect
hoses
and
harness
con-

nectors
from
fuel
sending
unit
and
fuel
pump
.

6
.
Unscrew
threaded
collar
from
fuel
pumplfuel
leve¡
sender
.
Slowly
withdraw
assembly
from
tank,allowing

fuelto
drain
off
.
See
Fig
.
7
.
0013187
&
0013194

Fig
.
6
.



Fuel
pump/leve¡
sender
terminal
identification
.
Check
resis-
tance
at
terminals
of
white
connectors
(arrows)
.



"
If
necessary,
push
leve¡
sender
arm
toward
fuel
pump

assembly
to
facilitate
removal
.

NOTE
-

BMW
special
tool
no
.
16
1
020
should
beused
to
re-
move
and
install
the
threaded
collar
.
Damage
to
the
collar
may
result
if
the
special
tool
is
not
used

WARNING
-

NOTE-



Fuel
may
be
spilled
.
Do
not
smoke
or
work
near

The
compensating
siphon
pump
(Fig
.
1)
maintains
the



heaters
or
other
fire
hazards
.

fuel
leve¡
between
the
right
and
left
tank
lobes
.
If
the
re-
sistances
are
different
between
the
left
and
right
send-
ers,
remove
the
senders
and
visually
inspect
the
leve)
in



7
.
Using
a
new
sealing
ring,
install
pump
and
sending
each
lobe
.
If
the
leve¡
is
different,
check
the
siphon
com-



unit,
being
sure
that
fuel
line
connections
point
in
same

pensating
pump
.



direction
as
they
carne
out
.

8
.
Reconnect
harnessconnector
and
hoses
.
Fill
tank
and

check
for
leaks
by
running
engine
.
Insta¡¡
access
cover

and
its
mountingscrews
.
Reconnect
negative
(-)
cable

to
battery
.

CAUTION
-

Before
starting
the
engine,
fill
the
fuel
tank
with
at
least
1
.5
gallons
(5liters)
of
fuel
.
The
pump
will
be
damaged
if
you
run
it
without
fuel
.

FUEL
LEVEL
SENDERS

160-
6



FUEL
TANK
AND
FUEL
PUMP

Fig
.
7
.



Fuel
sender
and
pump
assembly
.

To
operate
the
fuel
pump
for
testing
purposes
without
hav-
Fuel
leve¡
sender
(left
side),



ing
to
runthe
engine,
the
fuel
pump
relay
can
be
bypassed
to

removing
and
installing



powerthe
pump
directly
.

The
procedure
for
removing
and
replacing
the
left
side
fuel



To
runthe
fuel
pump,
remove
the
relay
and
connect
the
leve¡
sender
is
similar
tothat
used
for
the
right
side
.
There
is



socket
for
relayterminal
30
to
the
socket
for
relay
terminal
no
.
no
fuel
pump
on
the
left
side
.



87
with
afused
jumper
wire
.
Relay
terminal
identification
is
shown
in
Fig
.
9
.
After
completing
the
tests,
remove
the
jumper

wire
.

FUEL
PUMP

The
electric
fuel
pump
ís
mounted
in
the
fuel
tank
in
tandem
with
the
right
side
fuelleve¡
sender
.
The
fuel
pump
delivers
fuel
at
high
pressure
to
the
fuel
injection
system
.
A
pressure
regulator
maintains
system
pressure
.
The
quantity
of
fuel
sup-
plied
exceeds
demand,
so
excess
fuel
retums
to
the
fuel
tank
via
a
retum
líne
.
See
130
Fuel
Injection
for
more
information
on
system
pressure
and
the
fuel
pressure
regulator
.

NOTE
-

Fuel
pump
removalprocedures
are
given
earlier
under
Fuel
leve¡
sender
(right
side)
and
fuel
pump,
remov-
íng
and
installing
.

Fuel
Pump
Fuse
and
Relay

The
fuel
pump
is
operated
by
a
fuel
pump
relay
located
ín
the
power
distribution
box
.
The
fuel
pump
circuit
is
protected
by
fuse
no
.
18
located
in
the
power
distribution
box
.
See
Fig
8
.

FUEL
PUMP

0013142

Fuel



DM
E
PUMP
main
re
ay



rel
ay

0

aoo
o
~a

aao
ó

Fig
.
8
.



Fuel
pump
relay
location
in
power
distribution
box
.

The
DME
engine
control
module
(ECM)
and
the
DME
main

relay
supply
power
to
the
coi¡
sideof
the
fuel
pump
relay
.
Dur-

ing
starting,
the
fuel
pump
runs
as
long
as
the
ignition
switch
is
in
the
start
position
and
continues
to
run
oncethe
engine

starts
.
If
an
electrical
system
fault
interrupts
power
to
the
fuel
pump,
the
engine
will
notrun
.

Operating
fuel
pump
for
tests

CA
UTION-

Relay
locations
may
vary
.
Use
care
when
identify-
ing
relays
and
when
troubleshooting
the
electrical
system
at
the
fuselrelay
panel
.
The
fuel
pump
re-
¡ay
is
a
four
pin
relay
and
has
a
1.5
mm
2
red
wireat
terminal
30
in
the
relay
socket,
lf
in
doubt,
con-
sult
an
authorized
BMW
dealer
.

NOTE-

Thejumper
wire
shouldbe
1.5
mm2
(14
ga
.)
and
in-
clude
en
in-fine
fuse
holder
with
a16
amp
fuse
.
To
avoid
fuselrelay
panel
damage
fromrepeated
connect-
íng
and
disconnecting,
also
include
a
toggleswitch
.
A
heavy-duty
jumper,
BMW
tool
no
.
613
050,
fs
also
available
from
en
authorized
BMW
dealer
.

0013034,

If
the
pump
does
notrun
with
the
jumper
installed,
the
fault
could
be
in
the
fuel
pump
or
the
wiring
to
the
pump
.
Check
the
pump
and
its
wiring
as
described
below
.

Fig
.
9
.



Fuel
pump
relay
terminal
identification
.

Fuel
Pump
Electrical
Tests

Troubleshooting
of
any
fuel
pump
fault
should
begin
with

checking
the
fuel
pump
fuse
and
the
fuel
pump
relay
.
The
DME
main
relay
should
also
be
checked
.

NOTE-

Special
tools
are
requíred
for
some
of
the
tests
de-
scribed
here
.

Fuel
pump
electrical
circuit,
testing

The
fuel
pump
electrical
circuit
diagram
is
shown
in
Fig
.
10
.

3
.
If
fuel
pump
does
not
run,
disconnect
black
harness

connector
from
tank
sender
unit
.
With
jumper
wire
con-

nectedas
described
in
step
2
above,
check
for
positive

(+)
batteryvoltage
at
harness
connector
terminals
.
See
Fig
.
11
.

FUEL
TANK
AND
FUEL
PUMP



160-
7

From
Main
Relay
(+15
power
with
key
in
run



From
B+juretion
point
orstartposition)
(batteryvoRageatalltirnes)

'
.5
RD/Nrr



1
.5
RD

1
.5
GNNI

From
Engine



2
.5
GNNI
Control
Module



15
2
.5
GNNI

Ground
(below
center
console)

Fig
.
10
.
Fuel
pump
electrical
circuit
.

30

-~
Relay
Fuel
Pump

8~T

I



1

s
ám
61
Front
Power
I



a
1
Distribution
Box
I_
16

WIRING
COLOR
CODE

BK
-
BLACK
BR
-
BROWN
Fuel
Pump



RD



-



RED
(in-tank)
M
YL
YELLOWGN
-
GREENBU
-
BLUE
1
VI
-
VIOLET
GY
-
GREY
WT
-
WHITE
PK
-
PINK

0011946

4
.
If
voltage
and
groundare
present,
fuel
pump
is
proba-
bly
faulty
.
If
there
is
no
voltage,
check
wiring
From
fuel
pump
Reay
and
make
sure
Reay
is
functioning
correctly
.

CAUTION-

Fuseandrelaylocationsmayvary
.
Usecara
when



Fuel
pump
power
consumption,
testing

troubleshooting
the
electrical
system
at
the
fuselrelay
panel
.
To
resolve
problems
in
identify-



NOTE-
ing
a
relay,
see
en
authorízed
BMW
dealer
.



"
To
achieveaccurate
testresults,
fhe
battery
voltage
at
the
connector
should
be
approximately
13
volts
.
1.
Remove
rearseat
cushion,
pull
right
side
insulation
mat



Charge
the
battery
asnecessary
.

back
to
expose
fuel
tank
accesscover
.
Remove
cover



.
q
higher
than
normal
power
consumption
usually
fin-
to
expose
wiring
connections
.



dicates
a
worn
fuel
pump,
which
may
cause
intermit-
tentfuel
starvation
due
lo
pump
overheating
and
2
.
Remove
fuel
pump
relay
and
opérate
fuel
pump
as
de-



seizure
.
The
only
remedy
is
pump
replacement
.
Be
scribed
under
Operating
fuel
pump
for
tests
earlier
.



sure
to
check
that
thereturn
fine
and
the
pump
pickup
Pump
should
run
.
Disconnect
jumper
wire
when
fin-



are
not
obstructed
before
replacing
the
pump
.

ished
.
1
.
Remove
rear
seat
cushion,
pull
right
side
insulation
mal
back
to
expose
fuel
tank
accesscover
.
Remove
cover
to
expose
wiring
connections
.

2
.
Disconnect
(black)
harness
connector
from
fuel
pump
.

3
.
Connect
an
ammeter
and
an
insulated
jumper
wire
be-

tween
terminals
in
connector
and
corresponding
pump

terminals
.
See
Fig
.
12
.

FUEL
PUMP

Cooling
System
Pressure
Test



If
the
engine
overheats
and
no
other
cooling
system
testsindicate
trouble,
the
radiator
may
have
some
pluggedpassag-

A
cooling
system
pressure
test
is
used
to
check
for
internal



es
that
are
restricting
coolant
flow
.

leaks
.
Some
of
the
common
sources
ofinternal
leaks
are
a
faulty
cylinder
head
gasket,
a
cracked
cylinder
head,
or
a



Temperature
Gauge
Quick
Check
cracked
cylinder
block
.

The
coolant
temperature
sensor
is
located
on
the
intake
To
doa
cooling
system
pressure
test,
a
special
pressure



manifold
(left)
side
of
the
cylinder
head,
under
the
intake
man-
tester
is
needed
.



ifold
runners
.
See
Fig
.
2
.

WARNING
-

At
normal
operating
temperature
-
the
cooling
sys-
tem
is
pressurized
.
Allow
the
system
to
cool
before
opening
.
Release
the
cap
slowly
to
allow
sale
re-
tease
of
pressure
.

With
the
engine
cold,instan
a
pressure
tester
to
the
expan-

sion
tank
.
Pressurize
thesystem
to
the
specification
listed
be-

low
.
Pressure
should
not
drop
more
than
0
.1
bar
(1
.45
psi)
for

at
leakt
two
minutes
.
If
the
pressure
drops
rapidly
and
there
is
no
sign
of
an
externa¡
leak,
the
cylinder
head
gasket
may
be
faulty
.
Considera
compression
test
as
described
in
100
En-

gine-General
.

The
screw-on
type
expansion
tank
cap
should
also
be
test-

ed
using
a
pressure
tester
and
the
correct
adapter
.

Cooling
System
Test
Pressure

"
Radiator
test
pressure
.........
.
1
.5
bar
(21
.75
psi)

"
Radiator
cap
test
pressure
..
.
........
2
bar
(29
psi)

CA
UTION-

Exceeding
the
speclfied
test
pressure
could
dam-
age
the
radiatoror
other
system
components
.

Carefully
inspect
the
radiator
cap
for
damage
.
Replace
a

faulty
cap
or
a
damaged
cap
gasket
.

Thermostat
Quick
Check



In
later
models,
the
ECT
sensor
and
the
gauge
sender
are
combined
into
one
sender
unit
.
For
wire
colors
refer
to
Table
a
.
To
check
if
the
thermostat
is
opening
and
coolant
is
circulat-

ing
through
the
radiator,
allow
a
cold
engine
to
reach
operat-

ing
temperature
(temperature
gauge
needieapproximately

centered)
.
Shut
off
engine
.
Feel
the
top
radiator
hose
.
If
the

hose
is
hot
to
the
touch,
the
coolant
is
probably
circulating
cor-
rectly
.
If
there
are
any
cool
areas
in
the
hose
or
radiator,
cool-

ant
flow
to
the
radiator
is
probably
restricted
.
Check
for
a
faulty

thermostat
or
aplugged
radiator
.

NOTE-

A
thermostat
that
is
stuck
open
will
cause
the
engine
to
warmup
slowly
and
run
belownormal
temperature
at
highway
speed
.
A
thermostat
that
is
stuck
closed
will
re-

strict
coolant
flow
to
the
radiator
and
cause
overheating
.

RADIATOR
AND
COOLING
SYSTEM



170-
3

U
.¡ig
.v

Fig
.
2
.
Temperature
gauge
sender
on
M44
engine
.
Temperature
gauge
sender
location
is
similar
on
al]
engines
.

In
early
models,
the
engine
coolant
temperature
(ECT)
sen-

sor
for
the
fuel
injection
and
the
coolant
temperature
gauge

sender
are
located
side
by
side
.

Table
a
.
Coolant
Temperature
Sensor
Wire
Colors

Function



Sensor



Terminal



Wire
colors
location
number

Two
sensors
:
Temperature
Rear
1
Brown/violet
gauge
sender



2



Brown/yellow
ECT
sensor



Front



1



Brown/red
2



Brown
or
Brown/black

One
sensor
:
Temperature
Dual
1
Brown/yellow
gauge
sender



sensor



2



Brown/violet
ECT
sensor



3



Brown/red
4
Brown/black
or
Grey/black

TROUBLESHOOTING

WARNING

Your
common
sense,
good
judge-
ment,
and
general
alertness
are
cru-
cial
tosafe
and
successful
service
work
.
Before
attempting
any
work
on
your
BMW,
read
the
warnings
and
cautions
on
page
vi¡
and
the
copyright

page
at
the
frontof
the
manual
.
Review
these
warnings
and
cautions
each
time
you
prepare
to
work
on
your
BMW
.
Please
also
read
any
warnings
and
cautions
that
accom-
pany
the
procedures
in
the
manual
.

Fuel
pressure
regulator
See
Fuel
injection
Fue]
pump
general
information
160-1
electrical
tests
160-7
power
consumption,
testing
160-7
delivery
tests160-8
delivery
volume,
testing
g
160-9
electrical
circuit,
checking
160-7
fuse
and
relay
160-6
level
sender
See
pump/fuel
leve¡
sender
operating
fuel
pump
for
tests
160-6
pump/fuel
level
sender
(left
side),
removing/installing
160-6
pump/fuel
leve¡
sender
(right
side),
removing/installing
160-5
relieving
fuel
pressure
and
connecting
fue¡
pressure
gauge
160-8
Fueltank
and
lines
general
information
160-1
draining
160-2
evaporative
control
system
160-4
leve¡
senders,
testing
160-5
removing/installing
160-3
Fundamentals
for
the
do-it-yourself
owner
general
information
010-1
advice
for
the
beginner
010-4
cleanliness
010-4
electrical
testing
010-6
gaskets
and
seals
010-5
non-reusable
fasteners
010-5
planning
ahead
010-4
tightening
fasteners
010-5
wire
repairs
010-6
buying
parts
010-6
genuine
BMW
parts
010-6
information
you
need
to
know
010-7
non-returnable
parts
010-7
emergencies
010-11brake
fluid
leve¡
010-13
car
will
not
start
010-11
changinga
tire
010-11
check
enginewarning
light
010-13
dim
Iights
010-13
jump
starting
car
010-12
low
o]I
pressure
010-13
overheating
010-12

Emergencies
(cont
.)
spare
parts
kit
010-14
towing
010-13
gettingstarted
010-2
lifting
thecar
010-3
raising
car
safely
010-3
safety
010-2
working
under
car
safely
010-4
how
to
use
this
manual
010-2
warnings,
cautions
and
notes
010-2
service
010-7
tools
010-7
basic
tool
requirements010-8
BMW
specialtools
010-11
feeler
gauges
010-10
jack
stands
010-9
oil
change
equipment
010-9
torque
wrench
010-10
volt-ohm
meter
(VOM)
or
Multi-
meter010-10
Fuses
See
Electrical
component
locations

G

Gaskets
See
Fundamentals
for
the
do-it-
yourself
owner
Gearshift
See
Gearshift
linkage
Gearshift
linkagegeneral
information
250-1
automatic
shiftlock,
checking
function
250-5
automatic
transmission
gearshift
250-
3
gear
position/neutral
safety
switch,
replacing
(automatic
transmission)
250-4
gearshift
lever,
installing
(manual
transmission)
250-2
gearshift
lever,
removing
(manual
transmission)
250-1
gearshift
mechanism,
adjusting
(automatictransmission)
250-3
manual
transmission
gearshift
250-1
shift
interlock,
checking
function
(automatic
transmission)
250-6Glass
See
Door
windows
Glove
compartment
See
Interior
trim
Grille
See
Exterior
trim,
bumpers
Guibo
(flex
disc)
See
Driveshaft

Handle,
door
See
Doors
Hardtop
See
Body-general
Headlight
See
Exterior
lighting
Headlight
switch
See
Switches
and
electrical
accessoriesHeater
box
See
Heating
Heater
core

See
Heating
Heater
valve
See
Heating
Heating
general
information
640-1
air
distribution
motors
640-9
air
distribution
motor,
replacing
(rotary
knob)
640-10
blower
motor,
removing/installing
640-1blower
motor
resistor
pack,
replacing
640-3
control
head
640-7
removing/installing
(digital-display)
640-8
removing/installing
(rotary
knob)
640-7
control
module
removing/installing
(digital-display)
640-8
removing/installing
(rotary
knob)
640-8
heater
box,
removing640-4
heater
core,
replacing
640-6
heater
core
temperature
sensor,
replacing
640-7
heater
valve,
replacing
640-3
rear
window
blower
(convertible
models)
640-10
reas
window
defogger
640-10sensor
fan
forinterior
temperature,
replacing
640-9warnings
and
cautions
640-11
Hood
See
Fenders,
engine
hood

Idle
speed
See
Maintenance
program
Idle
speed
control
valve
See
Fuel
injection
Ignition
switch
See
Switches
and
electrical
accessories

INDEX
5

6
INDEX

Ignition
system
general
information
120-1basictroubleshooting
principies
120-3camshaft
position
(CMP)
sensor
120-
6

camshaft
positíon
(CMP)
sensor,
replacing
(4-cylinder
engine)
120-6camshaft
position
(CMP)
sensor,
replacing
(6-cylinder
engines)
120-7
checking
for
spark
120-3
crankshaftposition/rpm
sensor
120-5
crankshaft
position/rpm
sensor,
testing/replacing
(front
mounted
sensor)
120-6
crankshaft
positíon/rpm
sensor,
testing
(rear
mounted
sensor)
120-6
disabling
ignition
system120-2
ignition
coil,
testing
and
replacing
(4-
cylinder
engines)
120-3
ignition
coil,
testing
and
replacing
(6-
cylinder
engines)
120-4
ignítion
firing
order
120-7
ignition
system
diagnostics
120-3
ignition
system
schematics
120-7
ignition
system
service
120-3knock
sensors,
replacing
120-7warnings
and
cautions
120-2
Inspectíon
I
and
Inspection
II
See
Maintenanceprogram
Instrumentpanel
See
interior
trim
Instruments
general
information
620-1
instrument
cluster,
removinglinstalling
620-1
instrument
cluster,
self-testing
620-1
instrument
cluster
bulbs,
replacing
620-2
multi-information
display
(MID),
620-4
multi-information
display
(MID),
removing/installing
620-4
odometer
coding
plug,
replacing
620-
2
vehicle
speed
sensor,
replacing
620-3
Intake
manifold
4-cylinder
engíne,
removing
113-3
6-cylinder
engine,
removing
113-11
See
alsoCylinder
head
removal
and
installation
Intake
air
temperaturesensor
See
Fuel
injection
Interior
trim
general
information
513-1
center
console,
removing/installing
513-1
dashboard,
removing/installing
513-3
glove
compartment,
removing/
installing
513-2
lower
left
dash
panel,
removing/
installing
513-2

J

Jump
startíng
010-12

K

Knock
sensor
See
Ignition
system
L

Leather
upholstery
See
Maíntenance
program
Leve¡
sender
See
Fuel
pump
Lubrication
system
general
information
119-1
oil
pan,
removing/installing
(4-cylinder
engines)
119-2
oil
pan,
removing/installing
(6-cylinder
engine,
1992models)119-4
oil
pan
119-2
oil
pan,
removing/installing
(6-cylinder
engine,
1993
and
later
models)
119-6
oil
pressure,
checking
119-1
oil
pressure
warningsystem,
testing
119-2
oil
pump
119-8
oil
pump,
removing/installing
(4-cylinder
engine)
119-8
oil
pump,
removing/installing
(6-cylinder
engine)
119-9
troubleshooting
119-1

M

Maíntenance
program
general
information
020-2
accelerator
and
throttle
linkage
020-13
air
filter,
replacing
020-11
automatic
transmission
fluid
020-8
automatic
transmission
service
020-18
battery,
checking
and
cleaning
020-12
battery,
replacing
020-12
BMW
service
indicator
020-2
body
and
hinges,
lubricating
020-19
brake
fluid
020-9
brake
fluid,
replacing
020-17
brake
pad/rotor
wear,
checking
020-17
brake
system,
inspecting
020-17
clutch
fluid,
checking
020-19
cooling
system
service
020-14
drive
axle
joint
boots,
inspecting
020-19
engine
coolant
(anti-freeze)
020-9
engine
drive
belts
020-13
engine
oil,
checking
leve¡
020-9

Maintenance
program
(cont
.)
engine
oil
and
filter,
changing020-9engine
oil
service
020-9
exhaust
system,
inspecting
020-18
exterior
washing020-20
final
drive
gear
oil
020-9
final
drive
oil
level,
checking
020-18
front
suspension
and
steering

linkages,
inspecting
020-18
fuel
filter,
replacing
020-16
fuel
tank
and
fuel
lines,
inspecting
020-19
¡dle
speed
020-12
inspection
I
and
inspection
11
020-2
interior
care020-20
leather
upholstery
and
trim
020-20
maintenance
tables
020-3
manual
transmission
fluid,
checking
and
filling
020-18manual
transmission
fluid
020-8
manual
transmission
service
020-18oxygensensors
020-15
parking
brake,
checking
020-17
polishing
020-20
poly-ribbed
belt,
replacing
020-13
power
steering
fluid
020-9
power
steering
fluid,
checking
leve¡
020-14
rear
suspension,
inspecting
020-18
resetting
service
indicator
020-3
seat
belts
020-20
spark
plugs,
replacing
020-11
special
cleaning
020-20
tires,
checking
inflation
pressure
020-17
tires,
rotating
020-17
v-belt,
replacing
020-13
washing
chassis
020-20waxing020-20
windshield
wiperblade
maintenance
020-19
wheels,
aligníng
020-17
Manual
transmission
See
also
Maintenance
program
See
also
Transmission-general
general
information
230-1
back-up
light
switch,
replacing
230-2
inputshaft
sea¡,
replacing
(transmission
installed)
230-5
output
shaftsea¡,
replacing
(transmission
installed)
230-4
selector
shaft
sea¡,
replacing
(transmission
installed)
230-3
transmission
fluid,
replacing
230-2
transmission
fluidlevel,
checking
230-2
transmission
fluid
service
230-1
transmission
removal
and
installation
230-5
transmission,
removing/installing
230-
6
transmission
service
230-2
Mass
air
flow
sensor
See
Fuel
Injection