Honda Civic. Manual — part 312

VACUUM PUMP DIAGNOSIS

Basic timing incorrect

Reset timing, see

FUEL SYSTEMS

EGR valve malfunction

Replace EGR valve

Internal injection pump malfunction

Replace injection

pump, see FUEL

SYSTEMS

Incorrect injector pump housing pressure

Check pressure, see

FUEL SYSTEMS

Engine Overheating

Cooling system leaks

Check cooling system

and repair leaks

Belt slipping or damaged

Check tension and/or

replace belt

Thermostat stuck closed

Remove and replace

thermostat, see

ENGINE COOLING

Head gasket leaking

Replace head gasket

Oil Light on at Idle

Low oil pump pressure

Check oil pump

operation, see

ENGINES

Oil cooler or line restricted

Remove restriction

and/or replace cooler

Engine Won't Shut Off

Injector pump fuel solenoid does not return fuel
valve to OFF position

Remove and check

solenoid and replace if

needed

CONDITION & POSSIBLE CAUSE

CORRECTION

Excessive Noise

Loose pump-to-drive assembly screws

Tighten screws

Loose tube on pump assembly

Tighten tube

2008 Honda Civic EX

GENERAL INFORMATION Trouble Shooting - Basic Procedures

FUEL INJECTION TROUBLE SHOOTING

BASIC FUEL INJECTION TROUBLE SHOOTING CHART

Valves not functioning properly

Replace valves

Oil Leakage

Loose end plug

Tighten end plug

Bad seal crimp

Remove and re-crimp

seal

NOTE:

This is GENERAL information. This article is not intended to
be specific to any unique situation or individual vehicle
configuration. The purpose of this Trouble Shooting
information is to provide a list of common causes to
problem symptoms. For model-specific Trouble Shooting,
refer to SUBJECT, DIAGNOSTIC, or TESTING articles
available in the section(s) you are accessing.

CONDITION & POSSIBLE CAUSE

CORRECTION

Engine Won't Start (Cranks Normally)

Cold start valve inoperative

Test valve and circuit

Poor connection;vacuum or wiring

Check vacuum and

electrical connections

Contaminated fuel

Test fuel for water or

alcohol

Defective fuel pump relay or circuit

Test relay and wiring

Battery too low

Charge and test battery

Low fuel pressure

Test pressure regulator

and fuel pump, check

for restricted lines and

filters

No distributor reference pulses

Repair ignition system

as necessary

Open coolant temperature sensor circuit

Test sensor and wiring

Shorted W.O.T. switch in T.P.S.

Disconnect W.O.T.

2008 Honda Civic EX

GENERAL INFORMATION Trouble Shooting - Basic Procedures

switch, engine should

start

Defective ECM

Replace ECM

Fuel tank residual pressure valve leaks

Test for fuel pressure

drop after shut down

Hard Starting

Disconnected hot air tube to air cleaner

Reconnect tube and

test control valve

Defective Idle Air Control (IAC) valve

Test valve operation

and circuit

Shorted, open or misadjusted T.P.S.

Test and adjust or

replace T.P.S.

EGR valve open

Test EGR valve and

control circuit

Poor Oxygen sensor signal

Test for shorted or

circuit

Incorrect mixture from PCV system

Test PCV for flow,

check sealing of oil

filter cap

Poor High Speed Operation

Low fuel pump volume

Faulty pump or

restricted fuel lines or

filters

Poor MAP sensor signal

Test MAP sensor,

vacuum hose and

wiring

Poor Oxygen sensor signal

Test for shorted or

open sensor or circuit

Open coolant temperature sensor circuit

Test sensor and wiring

Faulty ignition operation

Check wires for cracks

or poor con- nections,

test secondary voltage

with oscilloscope

2008 Honda Civic EX

GENERAL INFORMATION Trouble Shooting - Basic Procedures

Contaminated fuel

Test fuel for water or

alcohol

Intermittent ECM ground

Test ECM ground

connection for

resistance

Restricted air cleaner

Replace air cleaner

Restricted exhaust system

Test for exhaust

manifold back

pressure

Poor MAF sensor signal

Check leakage

between sensor and

manifold

Poor VSS signal

If tester for ALCL

hook-up is available

check that VSS

reading matches

speedometer

Ping or Knock on Acceleration

Poor Knock sensor signal

Test for shorted or

open sensor or circuit

Poor Baro sensor signal

Test for shorted or

open sensor or circuit

Improper ignition timing

See VEHICLE

EMISSION

CONTROL LABEL

(where applicable)

Check for engine overheating problems

Low coolant, loose

belts or electric

cooling fan inoperative

NOTE:

For additional electronic fuel injection trouble shooting
information, see the appropriate article in the ENGINE
PERFORMANCE section (not all vehicles have Computer
Engine Control articles). Information is provided there for

2008 Honda Civic EX

GENERAL INFORMATION Trouble Shooting - Basic Procedures