display MITSUBISHI MONTERO 1998 Owner's Guide
[x] Cancel search | Manufacturer: MITSUBISHI, Model Year: 1998, Model line: MONTERO, Model: MITSUBISHI MONTERO 1998Pages: 1501, PDF Size: 25.81 MB
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VACUUM DIAGRAMS article. Install hoses as necessary and go to step
20). If hoses are okay, go to next step.
14) Disconnect OFLV-to-EVAP canister hose at OFLV and EVAP
canister. Plug hose at OFLV end. Connect hand-held pressure/vacuum
pump to hose at EVAP canister end. Apply 0.9 psi. If pressure is not
maintained, replace hose. Go to step 20). If pressure is maintained,
go to next step.
15) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Connect hand-held pressure/vacuum pump to
OFLV. While monitoring scan tool, apply 0.42 psi. If scan tool reading
reaches 0.42 psi, go to next step. If reading does not reach 0.42 psi,
go to step 19).
16) Disconnect OFLV-to-EVAP canister hose at EVAP canister.
Connect hand-held pressure/vacuum pump to hose and apply 0.9 psi. If
pressure is not maintained, go to next step. If pressure is
maintained, go to step 18).
17) Disconnect EVAP purge solenoid-to-EVAP canister hose at
EVAP canister. Connect hand-held pressure/vacuum pump to hose.
Disconnect intake manifold plenum-to-EVAP purge solenoid at intake
manifold plenum. Operate vacuum pump several times to apply vacuum. If
vacuum leaks, replace EVAP canister. Go to step 20). If vacuum does
not leak, repair clog in hose between EVAP canister and EVAP Purge
solenoid. Go to step 20).
18) Disconnect EVAP canister-to-OFLV hose at OFLV. If vacuum
does not leak, repair clog in hose between EVAP canister and OFLV. Go
to step 20). If vacuum leaks, check fuel tank filler tube assembly. If
fuel tank filler tube assembly is okay, repair clog in hose between
OFLV and fuel cut-off valve. Go to step 20).
19) Replace fuel tank filler tube and OFLV-to-fuel cut-off
valve hose. While monitoring scan tool, apply 0.42 psi with hand-held
pressure/vacuum pump. If scan tool reading does not reach 0.42 psi,
replace fuel tank. Go to next step.
20) Road test vehicle and attempt to duplicate conditions
that caused original complaint. Recheck for DTCs. If no DTCs are
displayed, test is complete.
DTC P0500: VEHICLE SPEED SENSOR (VSS) CIRCUIT FAILURE
NOTE: Speedometer testing procedures for 3000GT are not available
from manufacturer at time of publication. For terminal
identification, see TERMINAL IDENTIFICATION.
For circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) If using scan tool, go to step 4). On 3000GT, go to step
3). On Montero, speedometer testing procedures using DVOM require
removal of instrument panel. Removal and installation of instrument
panel is basically an unbolt and bolt-on procedure.
2) DO NOT disconnect connectors. Using DVOM, check continuity
between indicated speedometer terminals. See Fig. 40. Ensure
continuity pulses on and off with speedometer shaft revolution. If
continuity is not as specified, replace speedometer. If continuity is
as specified, go to next step.
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specified VSS connector terminal. See
VSS VOLTAGE FEED CIRCUIT IDENTIFICATION table. If voltage is not 4.5-
4.9 volts, replace PCM. If voltage is as specified, condition required
to set DTC is not present at this time. Go to next step.
VSS VOLTAGE FEED CIRCUIT IDENTIFICATION TABLE
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Application Terminal No.
Montero ................................................ 1
3000GT ................................................. 3
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9) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P0505: IDLE CONTROL SYSTEM FAILURE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Procedures are provided by manufacturer for component
testing using an engine analyzer with oscilloscope capability. Refer
to manufacturer's operation manual for instructions in use of
oscilloscope. If using engine analyzer, go to step 3). If using scan
tool, go to next step.
2) Using scan tool, read Idle Air Control (IAC) position
sensor step (item 45). See IAC POSITION SENSOR STEP SPECIFICATIONS
table. If scan tool does not read as specified, replace IAC position
sensor. If readings are as specified, go to step 5).
IAC POSITION SENSOR STEP SPECIFICATIONS TABLE
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A/C Switch Position Standard Step Value
Off ................................................. 2-25
Off To On ............................ Increase From 10-70
( 1) ................................... Increase From 5-50
( 1) - Brakes applied. A/C Off on Montero. A/C On on 3000GT.
Move gear selector lever to Drive position.
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NOTE: Check wave pattern when idle speed increases when A/C is
turned on. Wave pattern display lasts less than one second.
3) Disconnect IAC motor connector. Install Test Harness
(MB998463) between IAC motor and connector. Using engine analyzer with\
oscilloscope capability, connect special patterns probe in sequence to
test harness terminals No. 1 (Red clip), 3 (Blue clip), 4 (Black cl\
ip)
and 6 (Yellow clip) or PCM terminals No. 4, 5, 17 and 18 respectively.\
Start engine and allow it to idle. Turn A/C on. Compare oscilloscope
wave pattern with known-good wave pattern. See Fig. 44. Turn engine
off. If wave pattern is not normal, go to next step. If wave pattern
is normal, fault is intermittent. See INTERMITTENT DTCS.
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9) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
10) Road test vehicle and attempt to duplicate conditions
that caused original complaint. Recheck for DTCs. If no DTCs are
displayed, test is complete.
DTC P0510: CLOSED THROTTLE POSITION (TP) SWITCH FAILURE
NOTE: Closed TP switch is built into TP sensor. For DTC P0510
test purposes, TP sensor will be referred to as closed
TP switch. For terminal identification, see TP sensor under
TERMINAL IDENTIFICATION . For circuit and wire color
identification, see L - WIRING DIAGRAMS article.
1) If using scan tool, go to step 3). Disconnect closed TP
switch connector. Check for continuity between closed TP switch
connector terminals No. 1 and 2 on Montero or No. 3 and 4 on 3000GT.
Go to next step.
2) Depress accelerator pedal. Continuity should not exist.
Release accelerator pedal. Continuity should exist. If continuity is
not as specified, replace TP sensor. If continuity is as specified, go
to step 4).
3) Using scan tool, read closed TP switch state (item 26).
With accelerator pedal released, scan tool should read ON. With
accelerator pedal slightly depressed, scan tool should read OFF. If
closed TP switch does not test as specified, replace TP sensor. If
closed TP switch tests as specified, disconnect closed TP switch
connector and go to next step.
4) On 3000GT, go to next step. On Montero, turn ignition
switch to OFF position. Disconnect PCM connector. Ground PCM connector
terminal No. 79. Using DVOM, check continuity between chassis ground
and closed TP switch connector terminal No. 2. If continuity does not
exist, repair wiring harness as necessary. If continuity exists, go to
next step.
5) Check continuity between chassis ground and closed TP
switch connector terminal No. 1 on Montero or No. 4 on 3000GT. If
continuity does not exist, repair wiring harness as necessary. If
continuity exists, go to next step.
6) Turn ignition switch to ON position. Check voltage between
chassis ground and closed TP switch connector terminal No. 2 on
Montero or No. 3 on 3000GT. If voltage is less than 4 volts, replace
PCM. If voltage is more than 4 volts, condition required to set DTC is
not present at this time. Go to next step.
7) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P0551: POWER STEERING PRESSURE (PSP) SENSOR CIRCUIT
PERFORMANCE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Using scan tool, read Power Steering Pressure (PSP) statu\
s
(item 27). Switch status should read ON when steering wheel is turned.\
If switch status is as specified, fault is intermittent. See
INTERMITTENT DTCS . If switch status is not as specified, go to next
step.
Page 773 of 1501
should be actuated when pressure is 218-290 psi. Gradually open
shutoff valve to decrease pressure. Check pressure when PSP switch is
de-actuated. PSP switch should de-actuate at 102-174 psi. Turn engine
off. If PSP operates as specified, go to next step. If PSP does not
operate as specified, replace PSP switch. Go to step 8).
5) Disconnect PSP switch connector. On 3000GT, go to next
step. On Montero, turn ignition off. Disconnect PCM connector. Ground
PCM connector terminal No. 54. Using DVOM, check continuity between
chassis ground and PSP switch connector terminal No. 1. If continuity
does not exist, repair wiring harness as necessary. If continuity
exists, go to next step.
6) Turn ignition on. Using DVOM, check voltage between ground
and PSP switch connector terminal No. 1. If battery voltage does not
exist, replace PCM. If battery voltage exists, go to next step.
7) Road test vehicle and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
test is complete.
DTC P0705: TRANSMISSION RANGE SENSOR CIRCUIT FAILURE
DTC P0705 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
DTC P1103 & P1104: TURBOCHARGER WASTEGATE SOLENOID CIRCUIT
FAILURE
NOTE: This test applies to 3000GT with turbocharger only. For
terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) If using scan tool, go to step 7). Remove vacuum hoses
from turbocharger wastegate solenoid. Disconnect solenoid harness
connector. Connect a vacuum pump to solenoid nipple "A". See Fig. 46.
Go to next step.
2) Using jumper wires, connect battery voltage and ground to
solenoid terminals. Ensure vacuum does not hold with nipple "B"
unplugged, and negative jumper wire connected. If solenoid does not
test as specified, replace solenoid. If solenoid tests as specified,
go to next step.
Fig. 46: Testing Turbocharger Wastegate Solenoid
Courtesy of Mitsubishi Motor Sales of America
3) Ensure solenoid holds vacuum with nipple "B" plugged, and
negative jumper wire connected. If solenoid does not test as
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specified, replace solenoid. If solenoid tests as specified, go to
next step.
4) Ensure solenoid holds vacuum with nipple "B" unplugged,
and negative jumper wire disconnected. If solenoid does not test as
specified, replace solenoid. If solenoid tests as specified, go to
next step.
5) Check resistance between solenoid terminals. If resistance
is not 36-44 ohms at 68
F (20C), replace solenoid. If resistance is
as specified, go to next step.
6) Remove turbocharger by-pass valve. Connect vacuum pump to
by-pass valve nipple. Apply 16 in. Hg of vacuum. Ensure vacuum holds
and valve begins to open. If by-pass valve does not test as specified,
replace by-pass valve. If by-pass valve tests as specified, go to step
8).
7) Turn ignition switch to ON position. Using scan tool, turn
turbocharger wastegate solenoid on and off (item 12). Clicking sound
should be heard. If clicking sound is not heard, go to next step. If
clicking sound is heard, go to step 10).
8) Disconnect solenoid connector. Turn ignition switch to ON
position. Using DVOM, check for voltage between chassis ground and
solenoid connector terminal No. 1. If battery voltage does not exist,
repair wiring harness as necessary. If battery voltage exists, go to
next step.
9) Turn ignition switch to OFF position. Disconnect PCM
connector. Ground PCM connector terminal No. 41. Check continuity
between chassis ground and solenoid connector terminal No. 2. If
continuity does not exist, repair wiring harness as necessary. If
continuity exists, go to next step.
10) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P1105: FUEL PRESSURE SOLENOID FAILURE
NOTE: This test applies to 3000GT turbo only. For terminal
identification, see TERMINAL IDENTIFICATION. For circuit and
wire color identification, see L - WIRING DIAGRAMS article.
1) If using scan tool, go to step 6). Remove vacuum hoses
from fuel pressure solenoid. Disconnect solenoid harness connector.
Connect a vacuum pump to solenoid nipple "A". See Fig. 47. Apply
vacuum and go to next step.
2) Using jumper wires, connect battery voltage and ground to
solenoid terminals. Ensure solenoid does not hold vacuum with nipple
"B" unplugged, and negative jumper wire disconnected. If solenoid does
not test as specified, replace solenoid. If solenoid tests as
specified, go to next step.
Fig. 47: Testing Fuel Pressure Solenoid
Courtesy of Mitsubishi Motor Sales of America
3) Ensure solenoid holds vacuum with nipple "B" plugged, and
negative jumper wire disconnected. If solenoid does not test as
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specified, replace solenoid. If solenoid tests as specified, go to
next step.
4) Ensure solenoid holds vacuum with nipple "B" unplugged,
and negative jumper wire connected. If solenoid does not test as
specified, replace solenoid. If solenoid tests as specified, go to
next step.
5) Check resistance between solenoid terminals. If resistance
is not 36-44 ohms at 68
F (20C), replace solenoid. If resistance is
as specified, go to step 7).
6) Turn ignition switch to ON position. Using scan tool, turn
fuel pressure solenoid on and off (item 09). Clicking sound should be
heard. If clicking sound is heard, go to step 9). If clicking sound is
not heard, go to next step.
7) Disconnect fuel pressure solenoid connector. Using DVOM,
check for voltage between chassis ground and fuel pressure solenoid
terminal No. 1. If battery voltage does not exist, repair wiring
harness as necessary. If battery voltage exists, go to next step.
8) Turn ignition switch to OFF position. Disconnect PCM
connector. Ground PCM connector terminal No. 48. Check continuity
between chassis ground and fuel pressure solenoid connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
9) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P1400: MANIFOLD DIFFERENTIAL PRESSURE (MDP) SENSOR
CIRCUIT FAILURE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Component testing procedure without using scan tool not
available from manufacturer at time of publication. Warm vehicle to
normal operating temperature and allow engine to idle. Go to next
step.
2) Using scan tool, read intake manifold pressure (item 95).\
See INTAKE MANIFOLD PRESSURE SPECIFICATIONS table. If scan tool does
not read as specified, replace MDP sensor. If scan tool reads as
specified, go to next step.
INTAKE MANIFOLD PRESSURE SPECIFICATIONS TABLE
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Application psi (kPa)
Montero .............................. 3.0-4.9 (20.6-34.0)
3000GT
DOHC
Non-Turbo ........................ 3.7-5.7 (25.5-38.9)
Turbo ............................ 4.2-6.2 (29.0-42.4)
SOHC ............................... 3.9-5.8 (26.5-39.9)
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3) Disconnect MDP sensor connector. Using DVOM, check
continuity between chassis ground and MDP sensor connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
4) Turn ignition switch to OFF position. With MDP sensor
connector disconnected, disconnect PCM connector. Ground PCM connector
terminal No. 92. Check continuity between chassis ground and MDP
sensor connector terminal No. 1. If continuity does not exist, repair
Page 776 of 1501
wiring harness as necessary. If continuity exists, go to next step.
5) Reconnect PCM connector. Turn ignition switch to ON
position. Check voltage between chassis ground and MDP sensor
connector terminal No. 3. If voltage is not 4.8-5.2 volts, replace
PCM. If voltage is as specified, condition required to set DTC is not
present at this time. Go to next step.
6) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P1600: SERIAL COMMUNICATION LINK MALFUNCTION
DTC P1600 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
DTC P1715: PULSE GENERATOR FAILURE
DTC P1715 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
DTC P1750: SOLENOID FAILURE
DTC P1750 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
DTC P1791: ENGINE COOLANT TEMPERATURE LEVEL INPUT TO TCM
DTC P1791 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
SUMMARY
If no hard DTCs (or only pass DTCs) are present, driveability\
symptoms exist, or intermittent DTCs exist, proceed to H - TESTS W/O
CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START,
etc.) or intermittent diagnostic procedures.
Page 874 of 1501
J - PIN VOLTAGE CHARTS
1998 Mitsubishi Montero
1998 ENGINE PERFORMANCE
Mitsubishi - Pin Voltage Charts
Diamante, Eclipse, Galant, Mirage, Montero, Montero Sport,
3000GT
INTRODUCTION
NOTE: Unless stated otherwise in testing procedures, perform all
voltage tests using a Digital Volt-Ohmmeter (DVOM) with a
minimum 10-megohm input impedance. Voltage readings may vary
slightly due to battery condition or charging rate.
Pin voltage charts are supplied to reduce diagnostic time.
Checking pin voltages at the PCM connector determines whether it is
receiving and transmitting proper voltage signals. Diagnostic charts
may also help determine if PCM harness is shorted or open.
TEST PROCEDURE
CAUTION: Shorting positive DVOM lead between connector terminal and
ground could damage vehicle wiring, sensor and PCM.
1) If necessary, remove Powertrain Control Module (PCM) to
access harness connector. For PCM location, see PCM LOCATION table.
Leave PCM connectors connected.
2) Using DVOM, backprobe terminals. Connect positive DVOM
lead to appropriate PCM terminal. Connect negative DVOM lead to PCM
ground terminal. For PCM terminal identification, see appropriate
chart. See Figs. 1-24.
3) All measurements are applicable to vehicle at normal
operating temperature at sea level. Unless otherwise noted, engine is
idling when specification requires engine running. Ensure transmission
shift selector is in Neutral or Park (as applicable). If DVOM displays\
measurement that is not within specification, see G - TESTS W/CODES
article.
PCM LOCATION TABLE
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Application Location
Eclipse 2.0L Non-Turbo ............ In Front of Left Front
Strut Tower
Mirage & Montero Sport .............. Behind Right Side Of
Instrument Panel (Glove Box)
Montero ........................... Right Front Kick Panel
All Others ......................... Behind Center Console
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Fig. 1: Identifying PCM Terminals (Diamante)
Courtesy of Mitsubishi Motor Sales of America
Page 1413 of 1501
axle backlash. If backlash is one inch or less, drive axle is not the
source of clunk noise.
Bearing Whine
Bearing whine is a high-pitched sound similar to a whistle.
It is usually caused by malfunctioning pinion bearings. Pinion
bearings operate at drive shaft speed. Roller wheel bearings may whine
in a similar manner if they run completely dry of lubricant. Bearing
noise will occur at all driving speeds. This distinguishes it from
gear whine, which usually comes and goes as speed changes.
Bearing Rumble
Bearing rumble sounds like marbles being tumbled. It is
usually caused by a malfunctioning wheel bearing. The lower pitch is
because the wheel bearing turns at only about 1/3 of drive shaft
speed.
Chatter On Turns
This is a condition where the entire front or rear of vehicle
vibrates when vehicle is moving. The vibration is plainly felt as well
as heard. Extra differential thrust washers installed during axle
repair can cause a condition of partial lock-up that creates this
chatter.
Axle Shaft Noise
Axle shaft noise is similar to gear noise and pinion bearing
whine. Axle shaft bearing noise will normally distinguish itself from
gear noise by occurring in all driving modes (Drive, cruise, coast and
float), and will persist with transmission in Neutral while vehicle is
moving at problem speed.
If vehicle displays this noise condition, remove suspect
axle shafts, replace wheel seals and install a new set of bearings.
Re-evaluate vehicle for noise before removing any internal components.
Vibration
Vibration is a high-frequency trembling, shaking or grinding
condition (felt or heard) that may be constant or variable in level
and can occur during the total operating speed range of the vehicle.
The types of vibrations that can be felt in the vehicle can
be divided into 3 main groups:
* Vibrations of various unbalanced rotating parts of the
vehicle.
* Resonance vibrations of the body and frame structures caused
by rotating of unbalanced parts.
* Tip-in moans of resonance vibrations from stressed engine or
exhaust system mounts or driveline flexing modes.
DRIVE AXLE - RWD TROUBLE SHOOTING
NOTE: This is GENERAL information. This article is not intended
to be specific to any unique situation or individual vehicle
configuration. The purpose of this Trouble Shooting
information is to provide a list of common causes to
problem symptoms. For model-specific Trouble Shooting,
refer to SUBJECT, DIAGNOSTIC, or TESTING articles available
in the section(s) you are accessing. For definitions
of listed noises or sounds, see DRIVE AXLE - NOISE DIAGNOSIS
under POWERTRAIN.
DRIVE AXLE (RWD) TROUBLE SHOOTING
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CONDITION POSSIBLE CAUSE CORRECTION
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full load. The Kent-Moore J-39021 is such a tool, though there are
others. The Kent-Moore costs around $240 at the time of this writing
and works on many different manufacturer's systems.
The second method is to use a lab scope. Remember, a lab
scope allows you to see the regular operation of a circuit in real
time. If an injector is having an short or intermittent short, the lab
scope will show it.
Checking Available Voltage At the Injector
Verifying a fuel injector has the proper voltage to operate
correctly is good diagnostic technique. Finding an open circuit on the
feed circuit like a broken wire or connector is an accurate check with
a DVOM. Unfortunately, finding an intermittent or excessive resistance
problem with a DVOM is unreliable.
Let's explore this drawback. Remember that a voltage drop due
to excessive resistance will only occur when a circuit is operating?
Since the injector circuit is only operating for a few milliseconds at
a time, a DVOM will only see a potential fault for a few milliseconds.
The remaining 90+% of the time the unloaded injector circuit will show
normal battery voltage.
Since DVOMs update their display roughly two to five times a
second, all measurements in between are averaged. Because a potential
voltage drop is visible for such a small amount of time, it gets
"averaged out", causing you to miss it.
Only a DVOM that has a "min-max" function that checks EVERY
MILLISECOND will catch this fault consistently (if used in that mode).\
The Fluke 87 among others has this capability.
A "min-max" DVOM with a lower frequency of checking (100
millisecond) can miss the fault because it will probably check when
the injector is not on. This is especially true with current
controlled driver circuits. The Fluke 88, among others fall into this
category.
Outside of using a Fluke 87 (or equivalent) in the 1 mS "min-\
max" mode, the only way to catch a voltage drop fault is with a lab
scope. You will be able to see a voltage drop as it happens.
One final note. It is important to be aware that an injector
circuit with a solenoid resistor will always show a voltage drop when
the circuit is energized. This is somewhat obvious and normal; it is a
designed-in voltage drop. What can be unexpected is what we already
covered--a voltage drop disappears when the circuit is unloaded. The
unloaded injector circuit will show normal battery voltage at the
injector. Remember this and do not get confused.
Checking Injector On-Time With Built-In Function
Several DVOMs have a feature that allows them to measure
injector on-time (mS pulse width). While they are accurate and fast to\
hookup, they have three limitations you should be aware of:
* They only work on voltage controlled injector drivers (e.g
"Saturated Switch"), NOT on current controlled injector
drivers (e.g. "Peak & Hold").
* A few unusual conditions can cause inaccurate readings.
* Varying engine speeds can result in inaccurate readings.
Regarding the first limitation, DVOMs need a well-defined
injector pulse in order to determine when the injector turns ON and
OFF. Voltage controlled drivers provide this because of their simple
switch-like operation. They completely close the circuit for the
entire duration of the pulse. This is easy for the DVOM to interpret.
The other type of driver, the current controlled type, start
off well by completely closing the circuit (until the injector pintle
opens), but then they throttle back the voltage/current for the
duration of the pulse. The DVOM understands the beginning of the pulse