fuel MITSUBISHI MONTERO 1998 Service Manual

setting, see ENGINE
PERFORMANCE
Vacuum leak Eliminate vacuum leak
EGR valve malfunction Replace EGR valve









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Poor Gasoline Cracked or broken vacuum Replace vacuum hoses
Mileage hoses
Vacuum leaks Repair vacuum leaks
Defective ignition wires Replace wires
Incorrect choke setting Readjust setting, see
ENGINE PERFORMANCE
Defective vacuum advance Replace vacuum advance
Defective spark plugs Replace spark plugs
Binding carburetor power Eliminate binding
piston
Dirt in carburetor jets Clean and/or replace
jets
Incorrect float adjustment Readjust float
setting, see FUEL
Defective power valve Replace power valve,
see ENGINE PERFORMANCE
Incorrect idle speed Readjust idle speed









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Engine Stalls Improper float level Readjust float level
Leaking needle valve and Replace needle valve
seat and seat
Vacuum leaks Eliminate vacuum
leaks









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VACUUM PUMP - DIESEL 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.
NOTE: Diesel engines mechanical diagnosis is the same as gasoline
engines for items such as noisy valves, bearings, pistons,
etc. The following trouble shooting covers only items
pertaining to diesel engines.
VACUUM PUMP (DIESEL) TROUBLE SHOOTING CHART









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CONDITION POSSIBLE CAUSE CORRECTION








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The noid light is an excellent "quick and dirty" tool. It can
usually be hooked to a fuel injector harness fast and the flashing
light is easy to understand. It is a dependable way to identify a no-
pulse situation.
However, a noid light can be very deceptive in two cases:
* If the wrong one is used for the circuit being tested.
Beware: Just because a connector on a noid light fits the
harness does not mean it is the right one.
* If an injector driver is weak or a minor voltage drop is
present.
Use the Right Noid Light
In the following text we will look at what can happen if the
wrong noid light is used, why there are different types of noid lights
(besides differences with connectors), how to identify the types of
noid lights, and how to know the right type to use.
First, let's discuss what can happen if the incorrect type of
noid light is used. You might see:
* A dimly flashing light when it should be normal.
* A normal flashing light when it should be dim.
A noid light will flash dim if used on a lower voltage
circuit than it was designed for. A normally operating circuit would
appear underpowered, which could be misinterpreted as the cause of a
fuel starvation problem.
Here are the two circuit types that could cause this problem:
* Circuits with external injector resistors. Used predominately
on some Asian & European systems, they are used to reduce the
available voltage to an injector in order to limit the
current flow. This lower voltage can cause a dim flash on a
noid light designed for full voltage.
* Circuits with current controlled injector drivers (e.g. "Peak
and Hold"). Basically, this type of driver allows a quick
burst of voltage/current to flow and then throttles it back
significantly for the remainder of the pulse width duration.
If a noid light was designed for the other type of driver
(voltage controlled, e.g. "Saturated"), it will appear dim
because it is expecting full voltage/current to flow for the
entire duration of the pulse width.
Let's move to the other situation where a noid light flashes
normally when it should be dim. This could occur if a more sensitive
noid light is used on a higher voltage/amperage circuit that was
weakened enough to cause problems (but not outright broken). A circuit\
with an actual problem would thus appear normal.
Let's look at why. A noid light does not come close to
consuming as much amperage as an injector solenoid. If there is a
partial driver failure or a minor voltage drop in the injector
circuit, there can be adequate amperage to fully operate the noid
light BUT NOT ENOUGH TO OPERATE THE INJECTOR.
If this is not clear, picture a battery with a lot of
corrosion on the terminals. Say there is enough corrosion that the
starter motor will not operate; it only clicks. Now imagine turning on
the headlights (with the ignition in the RUN position). You find they
light normally and are fully bright. This is the same idea as noid
light: There is a problem, but enough amp flow exists to operate the
headlights ("noid light"), but not the starter motor ("injector").
How do you identify and avoid all these situations? By using
the correct type of noid light. This requires that you understanding

the types of injector circuits that your noid lights are designed for.
There are three. They are:
* Systems with a voltage controlled injector driver. Another
way to say it: The noid light is designed for a circuit with
a "high" resistance injector (generally 12 ohms or above).
* Systems with a current controlled injector driver. Another
way to say it: The noid light is designed for a circuit with
a low resistance injector (generally less than 12 ohms)
without an external injector resistor.
* Systems with a voltage controlled injector driver and an
external injector resistor. Another way of saying it: The
noid light is designed for a circuit with a low resistance
injector (generally less than 12 ohms) and an external
injector resistor.
NOTE: Some noid lights can meet both the second and third
categories simultaneously.
If you are not sure which type of circuit your noid light is
designed for, plug it into a known good car and check out the results.
If it flashes normally during cranking, determine the circuit type by
finding out injector resistance and if an external injector resistor
is used. You now know enough to identify the type of injector circuit.
Label the noid light appropriately.
Next time you need to use a noid light for diagnosis,
determine what type of injector circuit you are dealing with and
select the appropriate noid light.
Of course, if you suspect a no-pulse condition you could plug
in any one whose connector fit without fear of misdiagnosis. This is
because it is unimportant if the flashing light is dim or bright. It
is only important that it flashes.
In any cases of doubt regarding the use of a noid light, a
lab scope will overcome all inherent weaknesses.
OVERVIEW OF DVOM
A DVOM is typically used to check injector resistance and
available voltage at the injector. Some techs also use it check
injector on-time either with a built-in feature or by using the
dwell/duty function.
There are situations where the DVOM performs these checks
dependably, and other situations where it can deceive you. It is
important to be aware of these strengths and weaknesses. We will cover
the topics above in the following text.
Checking Injector Resistance
If a short in an injector coil winding is constant, an
ohmmeter will accurately identify the lower resistance. The same is
true with an open winding. Unfortunately, an intermittent short is an
exception. A faulty injector with an intermittent short will show
"good" if the ohmmeter cannot force the short to occur during testing.
Alcohol in fuel typically causes an intermittent short,
happening only when the injector coil is hot and loaded by a current
high enough to jump the air gap between two bare windings or to break
down any oxides that may have formed between them.
When you measure resistance with an ohmmeter, you are only
applying a small current of a few milliamps. This is nowhere near
enough to load the coil sufficiently to detect most problems. As a
result, most resistance checks identify intermittently shorted
injectors as being normal.
There are two methods to get around this limitation. The
first is to purchase an tool that checks injector coil windings under

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

3800 engines were suffering from exactly this. The point is that a
lack of detail could cause misdiagnosis.
As you might have guessed, a lab scope would not miss this.
RELATIONSHIP BETWEEN DWELL & DUTY CYCLE READINGS TABLE (1)









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Dwell Meter (2) Duty Cycle Meter
1
.................................................... 1%
15 .................................................. 25%
30 .................................................. 50%
45 .................................................. 75%
60 ................................................. 100%
( 1) - These are just some examples for your understanding.
It is okay to fill in the gaps.
( 2) - Dwell meter on the six-cylinder scale.









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THE TWO TYPES OF INJECTOR DRIVERS
OVERVIEW
There are two types of transistor driver circuits used to
operate electric fuel injectors: voltage controlled and current
controlled. The voltage controlled type is sometimes called a
"saturated switch" driver, while the current controlled type is
sometimes known as a "peak and hold" driver.
The basic difference between the two is the total resistance
of the injector circuit. Roughly speaking, if a particular leg in an
injector circuit has total resistance of 12 or more ohms, a voltage
control driver is used. If less than 12 ohms, a current control driver
is used.
It is a question of what is going to do the job of limiting
the current flow in the injector circuit; the inherent "high"
resistance in the injector circuit, or the transistor driver. Without
some form of control, the current flow through the injector would
cause the solenoid coil to overheat and result in a damaged injector.
VOLTAGE CONTROLLED CIRCUIT ("SATURATED SWITCH")
The voltage controlled driver inside the computer operates
much like a simple switch because it does not need to worry about
limiting current flow. Recall, this driver typically requires injector
circuits with a total leg resistance of 12 or more ohms.
The driver is either ON, closing/completing the circuit
(eliminating the voltage-drop), or OFF, opening the circuit (causing \
a
total voltage drop).
Some manufacturers call it a "saturated switch" driver. This
is because when switched ON, the driver allows the magnetic field in
the injector to build to saturation. This is the same "saturation"
property that you are familiar with for an ignition coil.
There are two ways "high" resistance can be built into an
injector circuit to limit current flow. One method uses an external
solenoid resistor and a low resistance injector, while the other uses
a high resistance injector without the solenoid resistor. See the left
side of Fig. 1.
In terms of injection opening time, the external resistor
voltage controlled circuit is somewhat faster than the voltage
controlled high resistance injector circuit. The trend, however, seems
to be moving toward use of this latter type of circuit due to its
lower cost and reliability. The ECU can compensate for slower opening

WHEEL ALIGNMENT THEORY/OPERATION
1998 Mitsubishi Montero
GENERAL INFORMATION
Wheel Alignment Theory & Operation
ALL MODELS
* PLEASE READ THIS FIRST *
NOTE: This article is intended for general information purposes
only. This information may not apply to all makes and models.
PRE-ALIGNMENT INSTRUCTIONS
GENERAL ALIGNMENT CHECKS
Before adjusting wheel alignment, check the following:
* Each axle uses tires of same construction and tread style,
equal in tread wear and overall diameter. Verify that radial
and axial runout is not excessive. Inflation should be at
manufacturer's specifications.
* Steering linkage and suspension must not have excessive play.
Check for wear in tie rod ends and ball joints. Springs must
not be sagging. Control arm and strut rod bushings must not
have excessive play. See Fig. 1.
Fig. 1: Checking Steering Linkage
* Vehicle must be on level floor with full fuel tank, no
passenger load, spare tire in place and no load in trunk.
Bounce front and rear end of vehicle several times. Confirm