NO.4 HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK [LF, L3]

id0103008010b2

4

HARD TO START/LONG CRANK/ERRATIC START/ERRATIC CRANK

DESCRIPTION

• The starter cranks the engine at normal speed but the engine requires excessive cranking time before starting.
• The battery is in normal condition.

POSSIBLE CAUSE

• Spark leakage from high-tension leads
• Vacuum leakage
• Poor fuel quality
• Starting system malfunction
• Spark plug malfunction
• Air leakage from intake-air system
• Erratic signal from CKP sensor
• Erratic signal from CMP sensor
• Improper air/fuel mixture ratio control
• Air cleaner restriction
• IAC valve malfunction
• PCV valve malfunction
• Inadequate fuel pressure
• Purge solenoid valve malfunction
• MAF sensor contamination
• Restriction in exhaust system
• EGR valve malfunction (Unleaded gasoline model)
• Pressure regulator 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 REPAIR PROCEDURE [LF, L3].)
(See AFTER REPAIR PROCEDURE [LF, L3].)
Caution
• Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and the quick release connector. Always clean the 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
Inspect for following:
• Vacuum leakage
• Proper fuel quality (e.g. proper octane, contamination, winter/summer blend)
• Loose bands on the intake-air system
• Cracks on the intake-air system parts
• Air cleaner restriction
Are all items normal?
Yes
Go to the next step.
No
Service if necessary.
Repeat Step 1.
2
Connect the WDS or equivalent to the DLC-2.
Retrieve any KOEO and KOER DTCs.
Are any KOEO or KOER DTCs displayed?
Yes

DTC is displayed:

Go to the appropriate DTC test.
No

No DTC is displayed:

Go to the next step.
3
Is the engine overheating?
Yes
Go to symptom troubleshooting "No.17 Cooling system concerns - Overheating".
No
Go to the next step.
4
Inspect for cracks on high-tension leads.
Are there any cracks on the high-tension leads?
Yes
Repair the suspected high-tension leads.
No
Go to the next step.
5
Inspect the spark plugs.
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 a clogged fuel injector.
No
Install spark plugs on original cylinders.
Go to the next step.
6
Visually inspect the CKP sensor and the teeth of the crankshaft pulley.
Are CKP sensor and teeth of the crankshaft pulley normal?
Yes
Go to the next step.
No
Replace the malfunctioning parts.
7
Measure the gap between the CKP sensor and the teeth of the crankshaft pulley.

Specification

0.5-1.9 mm {0.020-0.75 in}

Is the gap within the specification?
Yes
Go to the next step.
No
Adjust CKP sensor.
8
Remove and shake the PCV valve.
Does the PCV valve rattle?
Yes
Go to the next step.
No
Replace the PCV valve.
9
Install a fuel pressure gauge between the fuel pipe and the fuel distributor.
Connect a jumper wire between the F/P terminal at the check connector in the main fuse block and ground.
Turn the ignition switch to the ON position.
Is the fuel line pressure correct with the ignition switch ON?
Yes
Go to the next step.
No

Zero or low:

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

High:

Replace the fuel pump unit.
10
Dose the fuel line pressure hold after the ignition switch is turned off?
Yes
Go to the next step.
No
Inspect the fuel injector.
If the fuel injector is normal, replace the fuel pump unit.
11
Disconnect the vacuum hose from purge solenoid valve and plug the open end of the vacuum hose. Attempt to the start engine.
Does the starting condition improve?
Yes
Inspect if purge solenoid valve sticks open.
No
Go to the next step.
12
Inspect the MAF sensor for contamination.
Is there any contamination?
Yes
Replace the MAF sensor.
No
Go to the next step.
13
Is there restriction in the exhaust system?
Yes
Inspect the exhaust system.
No
Go to the next step. (Unleaded gasoline model)
Go to Step 14. (Leaded gasoline model)
14
Inspect the engine condition while tapping the EGR valve housing. Does engine condition improve?
Yes
Replace the EGR valve.
No
Go to the next step.
15
Inspect the starting system.
Is the starting system normal?
Yes
Inspect for loose connectors or poor terminal contact. If normal, remove the EGR valve and visually inspect for a mechanically stuck EGR valve.
No
Repair or replace components if required.
16
Verify test results.
• If normal, return to the diagnostic index to service any additional symptoms.
• If the malfunction remains, replace the PCM.