NO.9 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE, SURGES [WLT-1, WLT-2]

id010396912900

9
Engine stalls/quits—acceleration/cruise
Engine runs rough—acceleration/cruise
Misses—acceleration/cruise
Buck/jerk—acceleration/cruise/deceleration
Hesitation/stumble—acceleration
Surges—acceleration/cruise
DESCRIPTION
•  Engine stops unexpectedly at the beginning of acceleration or during acceleration or while cruising.
•  Engine speed fluctuates during acceleration or cruising.
•  Engine misses during acceleration or cruising.
•  Vehicle bucks/jerks during acceleration, cruising or deceleration.
•  Momentary pause at the beginning of acceleration or during acceleration
•  Momentary minor irregularity in the engine output
POSSIBLE CAUSE
•  Poor fuel quality
•  Glow system malfunction
•  Starting system malfunction.
•  Air leakage from intake-air system
•  Intake-air system restriction
•  Turbocharger malfunction
•  Air cleaner restriction
•  Engine overheating
•  A/C system improper operation
•  Fuel line restriction
•  Fuel filter clogging
•  Fuel inlet-filter restriction or clogging
•  Incorrect fuel injection timing
•  Incorrect idle speed
•  Injection pump malfunction
•  Injection nozzle malfunction
•  Fuel leakage
•  Low engine compression
•  Clutch slippage

Diagnostic procedure

STEP

INSPECTION

ACTION
1
•  Is the idle speed stable?
Yes
Go to the next step.
No
Go to symptom troubleshooting "NO.7 ENGINE RUNS ROUGH/ROLLING IDLE.”
2
•  Is the engine overheating?
Yes
Go to symptom troubleshooting "NO.13 COOLING SYSTEM OVERHEATING.”
No
Go to the next step.
3
•  Does the symptom disappear after warm-up?
Yes
Go to the next step.
No
Go to Step 5.
4
•  Inspect the glow plug and glow plug relay.
•  Is the glow system operation normal?
Yes
Go to the next step.
No
Repair or replace any malfunctioning part according to the glow system operation results.
5
•  Connect the pressure gauge to A/C lines.
•  Turn the blower switch on.
•  Is the pressure within the specification?
Yes
Go to the next step.
No
A/C is always on:
•  Go to symptom troubleshooting "NO.19 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY."
For other symptoms:
•  Inspect the following:
―  Refrigerant charging amount
―  Cooling fan operation
6
•  Inspect the air cleaner and/or intake-air system for clogging or restriction.
•  Are the air cleaner and intake-air system normal?
Yes
Go to the next step.
No
Clean or replace if necessary.
7
Note
•  The following test should be performed on vehicles with the turbocharger system.
•  Inspect the hose bands between the following parts:
―  Turbocharger compressor housing and air cleaner
―  Turbocharger compressor housing and charge air cooler
•  Are the hose bands loose?
Yes
Retighten the hose bands.
If the concern is resolved, the inspection is completed.
If the concern still exists, go to the next step.
No
Go to the next step.
8
•  Inspect for improper operation, kinks, clogs, or disconnection on the wastegate actuator.
•  Is the actuator normal?
Yes
The turbocharger is normal.
Go to the next step.
No
Repair or replace as necessary.
If the concern is resolved, complete the inspection.
If the concern still exists, the turbocharger is normal.
Go to the next step.
9
•  Remove the injection nozzle.
•  Inspect the injection nozzle for the following:
―  Clogged nozzle
―  Seized needle valve
―  Incorrect valve opening pressure
―  Malfunctioning nozzle gasket
•  Is the injection nozzle normal?
Yes
Go to the next step.
No
Clogged nozzle or seized needle valve:
•  Disassemble and clean or replace the injection nozzle.
Incorrect valve opening pressure:
•  Adjust injection nozzle opening pressure.
Malfunctioning nozzle gasket:
•  Replace nozzle gasket.
10
Is there any restriction in exhaust system?
Yes
Repair or replace as necessary.
No
Go to the next step.
11
•  Inspect the fuel line for restriction.
•  Is any restriction found in the fuel line?
Yes
Repair or replace if necessary.
No
Go to the next step.
12
•  Inspect the fuel filter for clogging.
•  Is the fuel filter normal?
Yes
Go to the next step.
No
Replace the fuel filter cartridge.
13
•  Inspect the fuel-inlet filter for restriction and/or clogging.
•  Is the fuel-inlet filter normal?
Yes
Go to the next step.
No
Replace or cleanup the fuel-inlet filter.
Go to the next step.
14
•  Measure the engine compression.
•  Is the compression normal?
Yes
Go to Step 16.
No
Go to the next step.
15
•  Inspect the timing belt for the following:
―  Chipping of gear teeth
―  Low tension
―  Breakage damage or cracks
•  Is the timing belt normal?
Yes
Inspect for the following:
•  Burnt valve
•  Worn piston, piston ring or cylinder
•  Damaged cylinder head gasket
•  Damaged valve seat
•  Worn valve stem and valve guide
Repair or replace if necessary.
No
If the timing is incorrect, adjust the timing.
If the timing belt is not normal, replace the timing belt.
16
•  Inspect the injection timing.
•  Is the injection timing normal?
Yes
Inspect the following:
•  Clutch for slippage
•  FIP
If normal, remove and inspect the FIP.
No
Adjust injection timing.
17
•  Verify the test results. If normal, return to the diagnostic index to service any additional symptoms.