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Mitsubishi Montero (1991+). Manual - part 307

repair

One or More, But Carburetor idle mixture Readjust carburetor,

Not All Firing not balanced see ENGINE PERFORMANCE

Voltage Lines are

Higher Than Others EGR valve stuck open Clean and/or replace

valve

High resistance in spark Replace spark plug

plug wires wires

Cracked or broken spark Replace spark plugs

plug insulator

Intake vacuum leak Repair leak

Defective spark plugs Replace spark plugs

Corroded spark plug Replace spark plugs

terminals

One or More, But Curb idle mixture not Readjust carburetor,

Not All Firing balanced see ENGINE PERFORMANCE

Voltage Lines Are

Lower Than Others Breaks in plug wires Replace plug wires

causing arcing

Cracked coil tower causing Replace coil

arcing

Low compression Determine cause and

repair

Defective spark plugs Replace spark plugs

Corroded spark plugs Replace spark plugs

Cylinders Not Cracked distributor cap Replace distributor

Firing terminals cap

Shorted spark plug wire Determine cause and

repair

Mechanical problem in Determine cause and

engine repair

Defective spark plugs Replace spark plugs

Spark plugs fouled Replace spark plugs

BASIC DRIVEABILITY PROBLEMS TROUBLE SHOOTING TABLE

CONDITION POSSIBLE CAUSE CORRECTION

Hard Starting Binding carburetor linkage Eliminate binding

Binding choke linkage Eliminate binding

Binding choke piston Eliminate binding

Restricted choke vacuum Check vacuum lines

for blockage

Worn or dirty needle valve Clean carburetor, see

and seat ENGINE PERFORMANCE

Float sticking Readjust or replace

float see the ENGINE

PERFORMANCE section

Incorrect choke adjustment Reset choke adjustment

see ENGINE PERFORMANCE

Defective coil Replace coil

Improper spark plug gap Regap spark plugs

Incorrect ignition timing Reset ignition timing

see ENGINE PERFORMANCE

Detonation Over-advanced ignition Reset ignition timing

timing see ENGINE PERFORMANCE

Defective spark plugs Replace spark plugs

Fuel lines clogged Clean fuel lines

EGR system malfunction Check and repair EGR

system

PCV system malfunction Repair PCV system

Vacuum leaks Check and repair

vacuum system

Loose fan belts Tighten or replace

fan belts, see ENGINE

PERFORMANCE

Restricted airflow Remove restriction

Vacuum advance malfunction Check distributor

operation

Dieseling Binding carburetor linkage Eliminate binding

Binding throttle linkage Eliminate blinding

Binding choke linkage or Eliminate binding

fast idle cam

Defective idle solenoid Replace idle solenoid

see ENGINE PERFORMANCE

Improper base idle speed Reset idle speed, see

see ENGINE PERFORMANCE

Incorrect ignition timing Reset ignition timing

see ENGINE PERFORMANCE

Incorrect idle mixture Reset idle mixture,

setting see ENGINE PERFORMANCE

Faulty Incorrect ignition timing Reset ignition timing

Acceleration see ENGINE PERFORMANCE

Engine cold and choke too Adjust choke and

lean allow engine to warm-

Defective spark plugs Replace spark plugs

Defective coil Replace coil

Faulty Low Speed Clogged idle transfer slots Clean idle transfer

Operation slots, see FUEL

Restricted idle air bleeds Disassemble and clean

and passages carburetor, see FUEL

Clogged air cleaner Replace air filter

Defective spark plugs Replace spark plugs

Defective ignition wires Replace ignition wire

see ENGINE PERFORMANCE

Defective distributor cap Replace distributor

cap

Faulty High Speed Incorrect ignition timing Reset ignition timing

Operation see ENGINE PERFORMANCE

Defective distributor Replace advance

centrifugal advance mechanism

Defective distributor Replace advance unit

vacuum advance

Incorrect spark plugs or Check gap and/or

plug gap replace spark plugs

Faulty choke operation Check choke and

repair as required

Clogged vacuum passages Remove restrictions

Improper size or clogged Check jet size and

main jet clean, see FUEL

Restricted air cleaner Check filter and

replace as necessary

Defective distributor cap, Replace cap, rotor or

rotor or coil coil

Misfire at All Defective spark plugs Replace spark plugs

Speeds

Defective spark plug wires Replace spark plug

wires

Defective distributor cap, Replace cap, rotor,

rotor, or coil or coil

Cracked or broken vacuum Replace vacuum hoses

hoses

Vacuum leaks Repair vacuum leaks

Fuel lines clogged Remove restriction

Hesitation Cracked or broken vacuum Replace vacuum hoses

hoses

Vacuum leaks Repair Vacuum leaks

Binding carburetor linkage Eliminate binding

Binding throttle linkage Eliminate binding

Binding choke linkage or Eliminate binding

fast idle cam

Improper float setting Readjust float

setting, see FUEL

Cracked or broken ignition Replace ignition

wires wires

Rough idle, Incorrect curb idle or fast Reset idle speed, see

Missing or idle speed see ENGINE PERFORMANCE

Stalling

Incorrect basic timing Reset ignition timing

see ENGINE PERFORMANCE

Improper idle mixture Reset idle mixture,

adjustment see ENGINE PERFORMANCE

Improper feedback system Check feedback system

operation see ENGINE PERFORMANCE

Incorrect spark plug gap Reset spark plug gap,

see ENGINE PERFORMANCE

Moisture in ignition Dry components

components

Loose or broken ignition Replace ignition

wires wires

Damaged distributor cap or Replace distributor

or rotor cap or rotor

Faulty ignition coil Replace ignition coil

Fuel filter clogged or worn Replace fuel filter

Damaged idle mixture screw Replace idle mixture

screw, see FUEL

Improper fast idle cam Reset fast idle cam

adjustment adjustment, see TUNE-

see ENGINE PERFORMANCE

Improper EGR valve operation Replace EGR valve

Faulty PCV valve air flow Replace PCV valve

Choke binding or improper Reset choke or

choke setting eliminate binding

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