NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE

BHE010300103W14

12

LACK/LOSS OF POWER - ACCELERATION/CRUISE

DESCRIPTION

The performance is poor under a load (e.g., power loss when climbing hills).

POSSIBLE CAUSE

• Vacuum leakage
• Air leakage from intake-air system
• Air cleaner restriction
• Air suction at intake-air system (between MAF sensor and intake ports)
• Throttle body malfunction
• Improper SSV operation
• Improper APV operation*
• Improper VDI operation
• Improper operation of drive-by-wire control system (abnormal accelerator position and TP signals to PCM)
• Drive-by-wire control system in fail-safe function (abnormal accelerator position and TP signals to PCM)
• Poor fuel quality
• Inadequate fuel pressure
• Pressure regulator (integrated in fuel pump unit)
• Fuel pump mechanical malfunction
• Fuel line restriction or clogging
• Fuel injector improper operation
• Fuel injector malfunction (leakage, clogging, improper injection amount)
• Intermittent open or short in fuel pump related circuit
• Restriction in exhaust system
• Leakage or blockage exhaust manifold
• Purge solenoid valve malfunction (stuck open)
• Erratic signal from eccentric shaft position sensor
• Improper ignition timing control (abnormal ECT, IAT, MAF and knock sensor signals to PCM)
• Improper fuel injection control (abnormal MAF, ECT, front/rear HO2S and knock sensor signals to PCM)
• MAF sensor improper installation
• Spark leakage from high-tension leads
• Spark plug malfunction
• Incorrect spark plug heat range
• Engine overheating
• Low engine compression
– Engine internal malfunction
– Abnormal engine oil condition (viscosity, deterioration)
– Low oil pressure
– Excessive fuel pressure
– Air mixed in oil line
– Metering oil pump malfunction
• Leakage or clogged in oil pipe
• Leakage or clogged in oil nozzle
• Metering oil pump malfunction
• Improper metering oil pump control operation
• Improper A/C system operation
• Brake dragging
• Low tire pressure
• AT malfunction (AT)
• Improper operation of torque converter clutch control (AT)
• Clutch malfunction (MT)
Warning

The following troubleshooting flow chart contains fuel system diagnosis and repair procedures. Read the following warnings before servicing the fuel system:

• Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.
• Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete "BEFORE REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this manual.
(See BEFORE REPAIR PROCEDURE.)
(See AFTER REPAIR PROCEDURE.)
Caution
• Disconnecting/connecting quick release connector without cleaning it may possibly cause damage to fuel pipe and quick release connector. Always clean quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

1
Does the engine knock/ping/detonate?
Yes
Go to the symptom troubleshooting "No.13 Knocking/pinging/detonation-Acceleration/cruise".
No
Go to the next step.
2
Verify the following:
• Vacuum connection
• Air cleaner element
• Fresh air duct
• Air cleaner
• No air leakage from intake-air system
• No restriction of intake-air system
• Blockage of intake-air system (between MAF sensor and intake ports)
• MAF sensor installation
• Exhaust manifold (leakage, damaged)
• Fuel quality (e.g. proper octane, contamination, winter/summer blend)
• Tire pressure
Are all the items normal?
Yes
Go to the next step.
No
Service if necessary.
Repeat Step 2.
3
Connect the WDS or equivalent to the DLC-2.
Retrieve any continuous memory, KOEO and KOER DTCs.
If the engine stall condition exists, retrieve the continuous memory and the KOEO DTCs.
Are there any DTCs displayed?
Yes

DTC is displayed:

Go to the applicable DTC inspection.
(See DTC TABLE.)
No

No DTC is displayed:

Go to the next step.
4
Is the engine overheating?
Yes
Go to the symptom troubleshooting "No.17 Cooling system concerns - Overheating".
No
Go to the next step.
5
Connect the WDS or equivalent to the DLC-2.
Access the APP, RPM, MAF, O2S11, O2S12, TP_REL and VSS PIDs.
Drive the vehicle while monitoring the PIDs.
Are the PIDs within the specifications?
Yes
Go to the next step.
No

APP PID:

Inspect if the output signal APP sensor changes smoothly.

RPM PID:

Inspect the eccentric shaft position sensor and the related wiring harness for vibration or an intermittent open/short circuit or both. If normal, go to Step 10.

MAF PID:

Inspect for an intermittent open circuit of the MAF sensor and the related wiring harness.

O2S11 PID:

Inspect the front HO2S and the related wiring harness for vibration or an intermittent open or short circuit or both. If normal, go to Step 8.

O2S12 PID:

Inspect the rear HO2S and the related wiring harness for vibration or an intermittent concern or both. If normal, go to Step 8.

TP_REL PID:

Inspect if the TP sensor output increases smoothly.

VSS PID:

Inspect DSC system.
(See DTC Table.)
6
Inspect the knock sensor.
Is the knock sensor normal?
Yes
Go to the next step.
No
Replace the knock sensor.
7
Visually inspect the eccentric shaft position sensor and the teeth of the pulse wheel.
Are the eccentric shaft position sensor and the teeth of the pulse wheel normal?
Yes
Go to the next step.
No
Replace the malfunctioning parts.
8
Is a strong blue spark visible at each disconnected high-tension lead while cranking engine?
Yes
Inspect for the following:
• Spark plugs malfunction
• Spark plugs heat range
• Pulse wheel damaged on eccentric shaft
• Open or short circuit on the eccentric shaft position sensor
• Open or short between the eccentric shaft position sensor and PCM terminal 2U or 2X
If they are normal, go to the next step.
No
Inspect for the following:
• High-tension leads
• Ignition coils or connectors
9
Inspect the spark plug condition.
Is the spark plug wet, covered with carbon or grayish white?
Yes

Spark plug is wet or covered with carbon:

Inspect for fuel leakage from the fuel injector.

Spark plug is grayish white:

Inspect for clogged fuel injector.
No
Install the spark plugs on original rotors.
Go to the next step.
10
Perform the drive-by-wire control system operation inspection.
Does the drive-by-wire control system work properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the drive-by-wire control system operation inspection results.
11
Visually inspect the exhaust system part.
Is there any deformed exhaust system part?
Yes
Replace the suspected part.
No
Go to the next step.
12
Perform the fuel pump speed control operation inspection.
Does the fuel pump speed control operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts, according to the fuel pump speed control operation inspection results.
13
Install the fuel pressure gauge to the fuel line quick release connector.
Short the check connector terminal F/P to the body GND using a jumper wire.
Turn the ignition switch to the ON position.
Is the fuel line pressure correct with the ignition switch at ON position?
Yes
Go to the next step.
No

Zero or low:

Inspect for clogged fuel line.
If normal, replace the fuel pump unit.

High:

Replace the fuel pump unit.
14
Perform the fuel injector operation inspection.
Are the fuel injectors operating properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts, according to the fuel injector operation inspection results.
15
Inspect the fuel injectors for the following:
• Leakage
• Clogging
• Injection amount
Are the injectors normal?
Yes
Go to the next step.
No
Replace the fuel injector.
16
Perform the SSV operation inspection.
Does the SSV operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts, according to the SSV operation inspection results.
17
Perform the VDI operation inspection.
Does the VDI operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts, according to the VDI operation inspection results.
18
Note
• The following test is for 13B-MSP (High Power). Go to the next step for 13B-MSP (Standard Power).
Perform the APV control inspection.
Does the APV control operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts, according to the APV control inspection results.
19
Note
• The following test is for an engine stalling with the A/C on. If other symptoms exist, go to the next step.
Connect the pressure gauge to the A/C low and high side pressure lines.
Turn the A/C on and measure the low side and high side pressures.
Are the pressures within the specifications?
Yes
Go to the next step.
No
If the A/C is always on, go to the symptom troubleshooting "No.24 A/C is always on or A/C compressor runs continuously".
For other symptoms, inspect the following:
• Refrigerant charging amount
• Condenser fan operation
20
Inspect for the A/C cut-off operation.
Does the A/C cut-off work properly?
Yes
Go to the next step.
No
Inspect the A/C cut-off system components.
21
Disconnect the vacuum hose between the purge solenoid valve and the intake manifold at the quick release connector.
Plug the opening end of the vacuum hose.
Drive the vehicle.
Does the engine condition improve?
Yes
Inspect if the purge solenoid valve is stuck open mechanically.
Inspect the evaporative emission control system.
No
Go to the next step.
22
Perform the metering oil pump control inspection.
Does the metering oil pump control properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning parts, according to the metering oil pump inspection results.
23
Inspect the engine compression.
Is it normal?
Yes
Inspect the following:
• Ignition timing
• Internal transmission components (AT)
• Torque converter clutch control (AT)
• Clutch (MT)
• Brake system for dragging
• Knock sensor
No
Go to the next step.
24
Perform the metering oil pump control inspection.
Does the metering oil pump control operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
After that overhaul or replace the engine.
(See Engine Workshop Manual.)
25
Check the engine oil condition.
Is the engine oil low viscosity and/or is there a gasoline odor?
Yes
Replace engine oil.
Inspect the ECT sensor and the related wiring harnesses.
After that overhaul or replace the engine.
(See Engine Workshop Manual.)
No
Go to the next step.
26
Inspect the oil pressure.
Is the oil pressure within the specification?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
After that overhaul or replace the engine.
(See Engine Workshop Manual.)
27
Turn the ignition switch off.
Disconnect the fuel line quick release connector and install the fuel gauge to the fuel line.
Start the engine and run it at idle.
Measure the fuel line pressure at idle.
Is the fuel line pressure correct at idle?
Yes
Go to the next step.
No
Replace the fuel pump unit.
After that overhaul or replace the engine.
(See Engine Workshop Manual.)
28
Check the oil pipe between the metering oil pump and the metering oil nozzle.
Is there any air and/or clogging in the oil pipe?
Yes
Inspect and repair for leakage and/or clogging in the oil passage at engine.
After that overhaul or replace the engine.
(See engine Workshop Manual.)
No
Overhaul or replace the engine.
29
Verify test results.
• If normal, return to the diagnostic index to service any additional symptoms.
• If the malfunction remains, inspect the related Service Information and perform the repair or diagnosis.

*  :
13B-MSP (High Power)