signal MITSUBISHI MONTERO 1991 Owner's Guide

or alcohol
Intermittent ECM ground Test ECM ground
connection for
resistance
Restricted air cleaner Replace air cleaner
Restricted exhaust system Test for exhaust
manifold back
pressure
Poor MAF sensor signal Check leakage
between sensor and
manifold
Poor VSS signal If tester for ALCL
hook-up is available
check that VSS
reading matches
speedometer









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Ping or Knock on Poor Knock sensor signal Test for shorted or
Acceleration open sensor or
circuit
Poor Baro sensor signal Test for shorted or
open sensor or
circuit
Improper ignition timing See VEHICLE EMISSION
CONTROL LABEL (where
applicable)
Check for engine Low coolant, loose
overheating problems belts or electric
cooling fan
inoperative









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NOTE: For additional electronic fuel injection trouble shooting
information, see the appropriate article in the ENGINE
PERFORMANCE section (not all vehicles have Computer Engine
Control articles). Information is provided there for
diagnosing fuel system problems on vehicles with electronic
fuel injection.
IGNITION SYSTEM 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.
Ignition Secondary Trouble Shooting Chart








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START: Visually inspect Spark Plug Wires, Coil Wires, 

Plug Wire Boots, Rotor, and Distributor Cap for 

signs of damage. 

Free play in steering See STEERING COLUMN
shaft bearing article
Bearing loose on shaft See STEERING COLUMN
serrations article









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Clicking Noise Pump slippers too long See POWER STEERING PUMP
in Pump article
Broken slipper springs See POWER STEERING PUMP
article
Excessive wear or nicked See POWER STEERING PUMP
rotors article
Damaged cam contour See POWER STEERING PUMP
article









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Poor Return of Wheel rubbing against See STEERING COLUMN
Wheel turn signal SWITCHES article
Flange rubbing steering See STEERING COLUMN
gear adjuster article
Tight or frozen steering See STEERING COLUMN
shaft bearing article
Steering gear out of See POWER STEERING GEAR
adjustment article
Sticking or plugged See POWER STEERING PUMP
spool valve article
Improper front end See WHEEL ALIGNMENT
alignment article
Wheel bearings worn or See FRONT SUSPENSION
loose article
Ties rods or ball joints Check and replace if
binding necessary
Intermediate shaft joints See STEERING COLUMN
binding article
Kinked pressure hoses Correct or replace if
necessary
Loose housing head See POWER STEERING GEAR
spanner nut article
Damaged valve lever See POWER STEERING GEAR
article
Sector shaft adjusted See ADJUSTMENTS in POWER
too tight STEERING GEAR article
Worm thrust bearing See ADJUSTMENTS in POWER
adjusted too tight STEERING GEAR article
Reaction ring sticking See POWER STEERING GEAR
in cylinder article

Fig. 22: Single Injector - Known Good - Voltage Pattern
EXAMPLE #5 - CURRENT CONTROLLED DRIVER
These two known-good waveform patterns are from a Chrysler 3.
0L V6 VIN [3]. The first waveform, Fig. 23, is a dual trace pattern
that illustrates how Chrysler uses the rising edge of the engine speed
signal to trigger the injectors. The second waveform, Fig. 24, was
taken during hot idle, closed loop, and no load.