NO.4 HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK [L8, LF]

id0103a0801000

4 | HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK
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DESCRIPTION | • Starter cranks engine at normal speed but engine requires excessive cranking time before starting. (The battery is in normal condition.)
POSSIBLE CAUSE | • Air leakage from intake-air system • Air cleaner restriction • Poor fuel quality • Vacuum leakage • Erratic signal to ignition coil • Spark plug malfunction • Erratic signal from CKP sensor • Improper operation of electronic throttle control system • Inadequate fuel pressure • Pressure regulator malfunction (built-in fuel pump unit) • Purge solenoid valve malfunction • MAF sensor contamination • Incorrect MAF sensor ground voltage • Restriction in exhaust system • EGR valve malfunction • Starting system malfunction • PCV valve malfunction • PCM 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 SERVICE PRECAUTION" and "AFTER SERVICE PRECAUTION" described in this manual. (See BEFORE SERVICE PRECAUTION [L8, LF].) (See AFTER SERVICE PRECAUTION [L8, LF].) 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
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1 | Inspect the following: • Cracks on intake-air system parts • Intake-air system restriction (e.g. air cleaner element, fresh air duct) • Loose bands on intake-air system • Proper fuel quality (such as proper octane, contamination, winter/summer blend) • Vacuum leakage Is there any malfunction? | Yes | Repair or replace the malfunctioning part according to the inspection results. Repeat Step 1.
No | Go to the next step.
2 | Connect the M-MDS to the DLC-2. Perform the KOEO/KOER self test. (See KOEO/KOER SELF TEST [L8, LF].) Are any DTCs present? | Yes | Go to the appropriate DTC inspection. (See DTC TABLE [L8, LF].)
No | Go to the next step.
3 | Is the engine overheating? | Yes | Go to the symptom troubleshooting “NO.17 COOLING SYSTEM CONCERNS-OVERHEATING”. (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [L8, LF].)
No | Go to the next step.
4 | Inspect the ignition coil related wiring harness condition (intermittent open or short circuit) for all cylinders. Is there any malfunction? | Yes | Repair or replace the suspected wiring harness.
No | Go to the next step.
5 | Inspect the spark plug conditions. (See SPARK PLUG INSPECTION [L8, LF].) 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. Spark plug is grayish white: • Inspect the fuel injector for clogging. Repair or replace the malfunctioning part according to the inspection results.
No | Install the spark plugs on original cylinders. Go to the next step.
6 | Visually inspect the CKP sensor and teeth of crankshaft pulley. Is there any malfunction? | Yes | Repair or replace the malfunctioning part according to the inspection results.
No | Go to the next step.
7 | Attempt to start the engine at part throttle. Does the engine run smoothly at part throttle? | Yes | Perform the Electronic Throttle Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L8, LF].) Repair or replace the malfunctioning part according to the inspection results.
No | Go to the next step.
8 | Install fuel pressure gauge between the fuel pipe and the fuel distributor. Connect the M-MDS to the DLC-2. Perform the PID/DATA Monitor and Record Procedure. (See ON-BOARD DIAGNOSTIC TEST [L8, LF].) Turn the fuel pump on using FP PID in output state control of data logger function. Is the fuel line pressure correct? (See FUEL LINE PRESSURE INSPECTION [L8, LF].) | Yes | Go to the next step.
No | Zero or low: • Inspect the fuel pump and fuel pump relay related circuit. • Inspect for clogged fuel line. • If there is no malfunction: ― Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L8, LF].) • If there is a malfunction: ― Repair or replace the malfunctioning part according to the inspection results. High: • Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L8, LF].)
9 | Is the fuel line pressure held after the ignition switch is turned off? (See FUEL LINE PRESSURE INSPECTION [L8, LF].) | Yes | Go to the next step.
No | Inspect the fuel injector. (See FUEL INJECTOR INSPECTION [L8, LF].) If the fuel injector is normal: • Replace fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L8, LF].) If the fuel injector has a malfunction: • Replace fuel injector. (See FUEL INJECTOR REMOVAL/INSTALLATION [L8, LF].)
10 | Disconnect a vacuum hose from the purge solenoid valve and plug opening end of vacuum hose. Start the engine. Is the starting condition improved? | Yes | Inspect if the purge solenoid valve is stuck open. (See PURGE SOLENOID VALVE INSPECTION [L8, LF].) Repair or replace the malfunctioning part according to the inspection results.
No | Go to the next step.
11 | Inspect the MAF sensor the following: • Contamination • MAF sensor terminal B voltage (ground circuit) Is there any malfunction? | Yes | Repair or replace the malfunctioning part according to the inspection results.
No | Go to the next step.
12 | Visually inspect the exhaust system part. Is there any malfunction? | Yes | Repair or replace the malfunctioning part according to the inspection results.
No | Go to the next step.
13 | Inspect the engine condition while tapping the EGR valve housing. Does the engine condition improve? | Yes | Replace the EGR valve. (See EGR VALVE REMOVAL/INSTALLATION [L8, LF].)
No | Go to the next step.
14 | Inspect the starting system. (See STARTER INSPECTION [L8, LF].) Is there any malfunction? | Yes | Repair or replace the malfunctioning part according to the inspection results.
No | Go to the next step.
15 | Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [L8, LF].) Is there any malfunction? | Yes | Replace the PCV valve.
No | Inspect for loose connectors or poor terminal contact. If there is no malfunction: • Remove the EGR valve and visually inspect for mechanically stuck EGR valve.
16 | Verify test results. • If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [L8, LF].) • If malfunction remains, inspect related Service information perform repair or diagnosis. ― If vehicle repaired, troubleshooting completed. ― If vehicle not repaired or additional diagnostic information not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [L8, LF].)