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I Fuel Injection
Release injector locking clips at each injector and pry injector
wiring duct up off injectors.
Clamp off fuel supply line and fuel return line at end of fuel
rail. Disconnect fuel supply fuel return lines from fuel rail.
WARNING -
Clamp off the fuel lines and then wrap a clean shop towel
around the lines before removing them. Residual
fuelpres-
sure is present in the lines.
Fuel is discharged. Do not disconnect any wires that
could cause electrical
sparks. Do not smoke or work
near heaters or other fire hazards. Keep an approved
I fire extinguisher handy. I
- Remove fuel rail mounting fasteners
- Pull up on fuel rail and remove individual injectors by remov-
ing injector retaining clip and pulling injector from rail.
- Installation is reverse of removal. Fit new O-rings when in-
stalling injectors. For ease of installation, lightly lubricate in-
jector O-ring with
SAE9O gear lube.
Tightening torque Fuel rail to
intake manifold 10 Nm (89 in-lb)
Evaporative emissions, overview
On E39 MS 41 .I cars, the evaporative emissions system is
combined with the tank ventilation system. The evaporative
system is monitored by the ECM for correct purge operation
and leak detection.
The carbon (purge) canister is purged using engine vacuum
via the
purgevalve.The purgevalve (located nextto the mass
airflow sensor) is ECM controlled and regulates the purge
flow into the intake manifold. The valve is powered open and
closed by an internal spring.
If the evaporative emission valve circuit is faulty, a fault code
is set and the MIL is illuminated when OBD
II fault criteria are
exceeded. If the valve is mechanically faulty, poor driveability
may result and a mixture adaptation fault is stored in the
ECM.
The leak diagnosis pump (LDP) is activated by the ECM and
pressurizes the fuel tank and evaporative system as apart of
theOED I1 leakdetection monitor. If the LDP orthe LDP circuit
is defective, afault code is set and the MIL is illuminated when
OBD
I1 fault criteria are exceeded. The LDP is mounted the
left rear wheel well behind the fender liner.
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- -.
Fuel Injection
SIEMENS MIS 42.0 AND 43.0
When system faults are detected, a diagnostic trouble code
(DTC) is stored in the engine control module (ECM). The MIL
also illuminates
if an emissions-related fault is detected.
When faults arise, or
if the malfunction indicator lamp (MIL) is
illuminated, begin troubleshooting by connecting BMW ser-
vice tester
DISplus, MoDiC, GTI or equivalent scan tool. The
capabilities of OBD
II software has the potential to save hours
of diagnostic time and to help avoid incorrect component re-
placement and possible damage to system components.
CAUTION-
* The tests in this section may set fault codes (DTCs) in tlie
ECM and illuminate the MIL. After all testing is completed,
access and clear DTC fault
memory using an OBD I/ or
BMW compatible scan tool. See
OBD On-Board Diag-
nostics.
Only use a
dgital multimeter for electrical tests.
Relay positions can vary. Be sure to confirm
relayposi-
tion by identifying the wiring in the socket using the wir-
ing diagrams found in
ELE Electrical Wiring
Diagrams.
NOTE-
- OBD I1 fault memory. (including an illuminated MIL! can
only be reset using the special scan tool. Removing the
connector from the ECM or disconnecting the battery will
not erase the fault memory.
The BMW-dedicated 20-pin diagnostic
linlc connector
(DLC) is in the right rear of the engine compartment The
20-pin DLC is discontinued on models after
6/2000.
The 1 &pin OBD I1 diagnostic connector (arrow) is located
inside the car on the lower left dash panel.
The MS
42.0 and MS 43.0 systems manage the following
functions.
- Air:
Idle speed valve
Electronic throttle
Hot film mass air flow (MAF) sensor
Resonance-turbulence intake control
- Fuel:
* Fuel supply
Running losseslnon return
Fuel injection
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Fuel Injection
A faulty MAF sensor can produce the following problems:
Difficult to restart when engine is hot
Engine starts then stalls
* Engine starts and runs only with accelerator pedal de-
pressed
4 Disconnect electrical harness connector from MAF sensor
(B).
- Turn ignition on and checlc for voltage and ground at connec-
tor.
There should be ground at pin
1 and battery voltage at pin
3.
- If any faults are found, checlc for wiring breaks between
MAF sensor and ECM and between MAF sensor and main
DME relay.
NOTE-
Visually inspect the sensor for damage, missing or blocked
screens. The screens affect air flow calibration. Also inspect
the sealina
0-rinas where the sensor inserts into the air filter - - housing and intake boot. Ensure the pin connections are
clean and tight.
4 Connect a BMW-compatible scan tool or an OED II generic
scan tool.
Checlc air mass signal (load signal) with the engine
at idle. Raise idle speed and
checlc that load signal changes
with rpm.
CAUTION-
Be sure ignition is OFFbefore disconnecting or reconnecting
DME system components.
Remove MAF sensor:
Loosen intake boot clamp
(A).
Disconnect harness connector (6).
* Release clip from air filter housing (C) and remove sensor.
- Installation is reverse of removal.
No adjustment to MAF sensor is possible.
Check intake hoses for cracks and vacuum
lealts.
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Fuel lniection I
4 Remove complete air filter housing:
Disconnect electrical harness connector on mass air flow
sensor
(A).
Disconnect vacuum line at intake boot (B).
Loosen Intake air duct clamp (C).
Remove filter housing mounting screws
Disconnect air duct and
lift complete air filter housing and
MAF sensor out of engine compartment, pulling it forward
away from throttle housing.
- Pull throttle cable upwards out of rubber retainer and unhoolc
ball end of cable from throttle actuator.
4 Remove nuts and bolts (arrows) retaining wiring harness to
throttle housing.
- Working at throttle housing, turn harness plug counterclock-
wise and remove plug.
4 Working at side of intake manifold, disconnect electrical har-
ness connectors:
Idle control valve (A)
lntalce manifold resonance valve (B)
- Disconnect electrical harness connectors at oil pressure
sender and oil temperature sender at base of oil filter hous-
ing.
CO,l,> ti,, "F"bl,rl,irrm.,-AI ",",>ti
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/Fuel Injection
4 Remove dipstick guide tube:
Disconnect wiring harness brackets from tube (A).
Unclip fuel lines from dipstick tube
(El).
Remove lower guide tube mounting bolt (C). Pull out dip-
stick guide tube.
< If necessary, disconnect electrical harness connector at fuel
tank venting valve (A). Disconnect hose at quick disconnect
fitting (arrow).
Working at throttle housing, turn harness plug counterclock-
wise and disconnect. Remove throttle assembly mounting
fasteners (arrows) and pull assembly off manifold.
Installation is reverse of removal
Replace sealing ring between throttle assembly and intake
manifold.
0 Reattach throttle assembly harness connector with care.
Arrow on fully tightened connector must line up with corre-
sponding arrow on throttle assembly housing.
* Connect BMW test equipment or equivalent and carry out
throttle plate adaptation following the on-screen directions.
Reattach throttle cable and check cable adjustment as de-
scribed under Throttle cable, adjusting
(MS 42.0).
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130-36
[~uel Injection
4 Remove nuts and bolts (arrows) retaining wiring harness to
throttle housing.
- Working at throttle housing, turn harness plug countercloclc
wise and remove.
4 Working at side of intake manifold, disconnect electrical bar-
ness connectors:
Idle control valve (A)
Intake manifold resonance valve (B)
- Disconnect electrical harness connectors at oil pressure
sender and oil temperature sender at base of oil filter hous-
ing.
4 Remove dipstick guide tube:
Disconnect wiring harness brackets from tube
(A)
Unclip fuel lines from tube (B).
Remove lower guide tube mounting bolt (C).
Pull out dipstick guide tube.