NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed))


12	Lack/loss of power-acceleration/cruise
DESCRIPTION	• Performance is poor under load (e.g. power down when climbing hills).
POSSIBLE CAUSE	• Improper A/C system operation • Erratic signal or no signal from CMP sensor • Air leakage from intake-air system parts • IMCC malfunction • Purge control solenoid malfunction • EGR valve malfunction • Brake dragging • Erratic signal from CKP sensor • Low engine compression • Vacuum leakage • Poor fuel quality • Spark leakage from ignition coils • Air cleaner restriction • PCV valve malfunction • Improper valve timing due to jumping out of timing belt • Restriction in exhaust system • Intermittent open or short in fuel pump circuit • Inadequate fuel pressure • Fuel pump mechanical malfunction • Fuel leakage from fuel injector • Fuel injector clogging • Intermittent open or short of MAF sensor, TP sensor and VSS • ATX malfunction Warning • The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services: - 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 SERVICE PRECAUTION [AJ].) (See AFTER SERVICE PRECAUTION [AJ].)


STEP	INSPECTION		ACTION
1	• Verify following: - Vacuum connection - Air cleaner element - No air leakage from intake-air system - No restriction of intake-air system - Proper sealing of intake manifold and components attached to intake manifold: EGR valve, IAC valve - Fuel quality: proper octane, contamination, winter/summer blend • Are all items normal?	Yes	Go to next step.
1		No	Service as necessary. Repeat Step 1.
2	• Connect WDS or equivalent to DLC-2. • Turn ignition switch to ON (Engine OFF). • Retrieve any DTCs. • Is "PASSED" displayed?	Yes	No DTC is displayed: • Go to next step.
2		No	DTC is displayed: • Go to appropriate DTC test.
3	Is engine overheating?	Yes	Go to symptom troubleshooting "No.17 Cooling system concerns-Overheating".
3	Is engine overheating?	No	Go to next step.
4	• Connect WDS or equivalent to DLC-2. • Access RPM, MAF, TP and VSS PIDs. • Drive vehicle with monitoring PIDs. • Are PIDs within specification? (See PCM Inspection Using the SST (WDS or equivalent).)	Yes	Go to next step.
4		No	RPM PID: • Inspect CKP sensor and related harness for vibration and/or intermittent open/short circuit. MAF PID: • Inspect for intermittent open circuit of MAF sensor and related wire harness. TP PID: • Inspect if TP sensor output increases smoothly. VSS PID: • Inspect for intermittent open circuit of VSS and related wire harness.
5	• Visually inspect CKP sensor and teeth of crankshaft pulley. • Are CKP sensor and teeth of crankshaft pulley normal?	Yes	Go to next step.
5		No	Replace malfunctioning part.
6	• Inspect spark plug conditions. • Is spark plug wet, covered with carbon or grayish white?	Yes	Spark plug is wet or covered with carbon: • Inspect for fuel leakage from fuel injector. • Inspect ignition system for suspect cylinder. Spark plug is grayish white: • Inspect for clogged fuel injector.
6		No	Install spark plugs on original cylinders. Go to next step.
7	• Remove and shake PCV valve. • Does PCV valve rattle?	Yes	Go to next step.
7	• Remove and shake PCV valve. • Does PCV valve rattle?	No	Replace PCV valve.
8	• Inspect for restriction in the exhaust system. • Is there any restriction?	Yes	Inspect exhaust system.
8		No	Go to next step.
9	• Install fuel pressure gauge between pulsation damper and fuel distributor. • Connect jumper wire between F/P terminal at DLC in engine compartment and GND. • Turn ignition switch to ON (Engine OFF). • Is fuel line pressure correct with ignition switch at ON? (See FUEL LINE PRESSURE INSPECTION [AJ].)	Yes	Go to next step.
9		No	Zero or low: • Inspect fuel pump circuit. • Inspect for open fuel pump relief valve. • Inspect for fuel leakage inside pressure regulator. • Inspect for clogged main fuel line. High: • Inspect pressure regulator for high pressure cause. • Inspect for clogged fuel return line.
10	• Inspect IMCC operation. • Does IMCC work properly?	Yes	Go to next step.
10	• Inspect IMCC operation. • Does IMCC work properly?	No	Repair or replace malfunctioning part.
11	Note • Following test is for engine stall with A/C on concern. If other symptom exists, go to next step. • Connect pressure gauge to A/C low and high side pressure lines. • Turn A/C on and measure low side and high side pressures. • Are pressure within specifications?	Yes	Go to next step.
11		No	If A/C is always on, go to symptom troubleshooting "No.24 A/C always on/A/C compressor runs continuously". For other symptoms, inspect following: • Refrigerant charging amount • Condenser fan operation
12	• Inspect A/C cut-off operation. • Does A/C cut-off work properly?	Yes	Go to next step.
12		No	Inspect A/C cut-off system components.
13	• Disconnect vacuum hose between purge solenoid valve and intake manifold from purge solenoid valve side. • Plug opening end of vacuum hose. • Drive vehicle. • Does engine condition improve?	Yes	Inspect if purge solenoid valve is stuck open mechanically. Inspect EVAP control system.
13		No	Go to next step.
14	• Visually inspect CMP sensor and projections of camshaft pulley. • Are CMP sensor and projections of camshaft pulley normal?	Yes	Go to next step.
14		No	Replace malfunctioning part.
15	• Inspect EGR system. • Is EGR system normal?	Yes	Go to next step.
15	• Inspect EGR system. • Is EGR system normal?	No	Replace malfunctioning part.
16	• Is engine compression correct?	Yes	Inspect following: • Valve timing • Internal transaxle components • Brake system for dragging
16	• Is engine compression correct?	No	Inspect for cause.
17	• Verify test results. - If normal, return to diagnostic index to service any additional symptoms. - If malfunction remains, inspect related Service Information and perform repair or diagnosis. • If vehicle is repaired, troubleshooting completed. • If vehicle is not repaired or additional diagnostic information is not available, replace or reprogram PCM.