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1 17-72
Camshaft Timing Chain
4 Working at right side cylinder head loosen Intake camshaft
sprocket bolts
(arrows).
4 Secure left and right side camshafts in TDC position:
Use BMW special tool set
11 2 440.
- If necessary, turn camshaft so that special tools are
squarely seated on cylinder head.
Working at left cylinder head loosen
intake camshaft
sprocket bolts
(arrows).
CAUTION-
Counter hold camshaft with a 27mm open-end wrench while
loosening sprocket bolts. Grind wrench
if necessary to pre-
vent damage to head.
Remove BMW special tool
11 2 300 from crankshaft locking
tool bore.
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Camshaft Timing Chain1
lnstall timing chain and intake sprocket to intake camshaft on
right cylinder head. While pressing in on chain tensioner rail,
confirm camshaft flange bores (arrows) are centered in
sprocket mounting slots.
NOTE-
Pressing in on rail will remove slack and reposition sprockets.
If
necessarx remove sproclets and align bores centrally.
lnstall intake camshaft sensor gear with notch upward (ar-
row) at right cylinder head.
- Finger tighten mounting screws.
- lnstall remaining sprocket bolts to intake camshaft finger tight
at left cylinder head.
- Press timing chain tensioning rail against timing chain. lnstall
plastic wire
tie, to hold rail against chain.
- lnstall lower timing chain cover:
Clean sealing surfaces and check sleeves are properly
seated.
Apply a thin coat of Three Bond 1209
8 to front and back
of new seal. Also coat joints where block meets cylinder
heads and oil pan.
Initially hand tighten bolts in alternate sequence to firmly
seat cover.
Tighten fasteners to final specification in alternate
sequence.
Tightening torques Lower timing cover
M6 bolts 10 Nrn (89 in-lb)
M7 bolts 15 Nm (1 1 ft-lb)
ME bolts 22 Nm (1 6 ft-lb)
M10 bolts 47 Nm (35 ft-lb)
- Replace radial seal in lower timing chain cover, then reinstall
crankshaft hub, center bolt, and vibration damper. See
Crankshaft oil seal, replacing
(M62 and M62 TU engines).
- lnstall oil pan with new gasket. See 119 Lubrication Sys-
tem.
- Lock crankshaft in place with BMW special tool 11 2 300
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[camshaft Timina Chain Cylinders
1-4
11 2445 11 2 441
502116429;
Secure right side camshafts in TDC position using special
BMWtoolll 2445andll 2441.
- If necessary, turn camshaft with 27 mm wrench so that spe-
cial tools are squarely seated on cylinder head.
- Fit BMW special tool 11 2 443 to 11 2 4411445. Secure 11 2
443
to cylinder head with 11 2 444 installed into spark plug
bore.
I
< Secure right side camshafts in TDC position using special
Cylinders 5-8 BMW tool 11 2 442 and 11 2 446.
- If necessary, turn camshaft so that special tools are squarely
seated on cylinder head.
- Fit BMW special tool 11 2 443 to 11 2 4421446. Secure 11 2
443
to cylinder head with 11 2 444 installed into spark plug
bore.
- Lock cranltshaft in TDC position by inserting BMW special
tool
11 3 200 through tool bore at transmission bellhousing.
- Remove primary timing chain tensioner piston from right cyl-
~nder head upper timing cover.
4 Attach BMW special tool 11 3 390 into right cylinder head in
place of primary chain tensioner.
Using BMW special tool
00 9 250, tighten adjusting screw
on
11 3 390 to 0.7 Nm (6.3 in-lb).
NOTE-
BMW special fool 00 9 250 is a flexible shaft torque wrench.
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130-8
Fuel Injection
With ignition off, remove main relay (K6300) (arrow) in
E-box.
- With ignition on and relay installed, check for battery voltage
on terminal
2 (87).
4 Check for voltage at terminal 8 (30) on relay socket.
If battery voltage is present, relay has energized and is
functioning correctly.
Gmund from 6L (hot ~4th k~y key in Ern
2I '1
on position)
to
Fuel pump RdiWt Rd from Battery and other system components SOZI~O~~I~Y
If battery voltage is not present and all earlier tests are OK,
relay is faulty and should be replaced.
If
battery voltage is present continue testing.
If battery voltage is not present, check fuse 109 (80-amp
fusible link) under passenger seat carpet. See ELE Elec-
trical Wiring Diagrams.
- Reinstall relay and turn ignition on. Gain access to back side
of relay socket and check for ground on terminal
4 (85).
If ground is present continue testing.
If ground is not present, signal from ECM is missing. Check
NOTE-
If no faults are found during testing but power is not reaching
the
ECM or other components, check the fuses in the fuse
carrier
X8680 in the E-box.
wire
between ECM and relay.
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130-28
Fuel Injection
ECM Relay
4 Check for voltage at terminal 6 (30) at reiay socket
If battery voltage is present continue testing.
if battery voltage is not present, check fuse 109 (80-amp
fusible link) under passenger seat carpet. See 610 Electri-
cal
Component Locations.
- Reinstall relay and turn ignition on. Gain access to back side
of reiay socket and check for ground at terminal
4.
If ground is present continue testing.
If ground is not present, signal
from ECM is missing. Check
wire between ECM and relay.
- With ignition on and reiay installed, check lor battery voltage
at terminal
2.
If battery voltage is present, relay has energized and is
functioning correctly.
If battery voltage is not present and
ail earlier tests are OK,
relay is faulty and should be replaced.
NOTE-
If no faults are found during testing but power is not reaching
the ECM or other components, check the fuses
in the fuse
carrier
X8680 in the E-box.
Mass air flow (MAF) sensor, checking and
replacing
4 The hot f~lm mass air flow (MAF) sensor sends a varying volt-
age (approx. 0.5 - 4.5 vdc) to the ECM representing the mea-
sured
Intake air. The alr mass input signal is produced
electron~caily uslng an electrically heated metal fllm in the air
flow stream.
The ECM relay provides the operating voltage to the MAF
sensor. As air
flows through the sensor, the film is cooled. To
maintain the film at a constant temperature, additional current
is necessary. It is this additional current that is the basis lor
the input signal.
If there is no output signal from the MAF sensor, the ECM op-
erates the engine using the throttle position and engine rpm
inputs. A faulty MAF sensor illuminates the MIL.
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Fuel Injection I
4 Release spring clips (arrows) from fuel injectors and pull in-
jector electrical loom straight up to remove.
4 Check that ECM signal is present at injector connectors.
- Connect digital voltmeter to fuel injector harness plug.
Operate starter and
check for voltage pulse.
* Repeat for each injector.
- Remove fuel injectors by removing retaining clips
- Installation is reverse of removal:
Fit new O-rings when installing injectors. For ease of instal-
lation, lightly lubricate all fuel system O-rings with assem-
bly lubricant.
Check that injector electrical connections are correctly fit-
ted and that
injectors are fully seated prior to installing iuel
rail mounting bolts.
Mass air flow sensor (MAF), replacing
The MAF sensor is provided with operating power from the
ECM relay. Based on calculated intake air mass, the MAF
generates
avarying voltage (approx. 0.5 - 4.5 vdc) as an input
signal to the ECM.
4 Remove MAF sensor:
Remove upper air filter housing locking clips.
Unscrew and remove MAF sensor harness
(A).
Disconnect intake air temperature sensor harness (B).
Loosen hose clamp (C).
Remove upper filter housing with sensor.
- Installation is reverse of removal
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130-72
Fuel Injection
I Oxygen sensors, replacing
4 Four Bosch oxygen sensors (2 precatalytic converter sen-
sors and
2 post-catalytic converter sensors) provide a vary-
ing voltage signal
[0.2 vdc (max. lean) to 0.8 vdc (max. rich)]
to the ME
7.2 ECM representing oxygen content in the ex-
haust gas.
WARNING-
Exhaust manifolds and pipes can be hot enough to cause se-
rious burns. Wear suitable heavy gloves and other appropri-
ate protection.
- Using a special oxygen sensor socltet, remove the threaded
sensors from the exhaust system.
- If not already applied, coat the new oxygen sensor threads
with an anti-seize compound before installation. Do not get
compound on the sensor tip.
Tightening torque
Oxygen sensor to exhaust system
50 Nm (37 ft-lb)
Fuel injectors, removing and installing
The ME 7.2 system uses ball seat type fuel injectors. This de-
sign
prov:des precise seal'ng when the iniector is closed
therebv eiminalinq raw HC (unb~rned fue ) formalion in tne
intake.-~he fuel inkctors areswitched on and off by the ECM
at the ground side.
- Remove plastic cover from above fuel rail. See100 Engine
Removal and Installation.
- Disconnected battery negative (-) cable.
CAUTION-
Prior to disconnecting the battea read the battery discon-
nection cautions given at the front of this manual. See 001
General Warnings and Cautions.
- Remove both ignition coil covers.
Disconnect ignition coil connectors.
Remove left and right ignition coil ground wires,
4 Remove fuel injector loom boxes.
Loosen mounting fasteners
(A).
Disconnect electrical plugs (B and D).
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- Fuel Tank and Fuel pump]
Remove fuel pump
relay (arrow).
4 Connect relay socitet terminal 6 (redlviolet wire) to relay
socket terminal
2 (whitelblue wire) with a fused jumper wire.
After completing tests, remove jumper harness.
CA
UTIOG
Relay locations may vary Use care when identifying relays
and making electrical checks at
the fuse/relay panel. See
610 Electrical Component Locations for additional re-
lay information.
The fuel pump relay has a 1.5
md red/violet wire at
terminal
6 in the relay socket. Terminal2 has a 2.5md
white/blue wire. See ELE Electrical Wiring Diagrams
for additional wiring information.
NOTE-
* The fuel pump will run as soon as the jumper wire Is at-
tached.
The jumper wire should be 1.5
md (14 ga.) and include
an in-line fuse holder with a 15A fuse. To avoid
fuse/relay
panel damage from repeated connecting and disconnect-
ing, also include a toggle switch in the jumper harness.
- If pump does not run with jumper installed, fault could be in
fuel pump, fuses
F31 or F22 1 F54, or wiring to pump. Check
pump, fuses and its wiring as described below.
Fuel pump electrical circuit, testing
- The test given below assumes that the fuel pump relay circuit
is functioning correctly as described earlier. Access to the
pump is from below the rear seat bottom cushion.
- Remove rear seat lower cushion by lifting front edge off left
and right catches.