2000 HONDA CR-V intake system

Intake Air System
System Description
The system supplies air for all engine needs. lt consists of the intake air pipe, Air Cleaner, intake air duct, Throttle Body
(TB), ldle Air Control (lAC) Valve, fast idle thermo valve, and intake manifold. A resonator in the intake air pipe provides
additional silencing as air is drawn into the system.
INTAKE MANIFOLD
YEL| - - Fiom PGM'FI
BLK T MAIN RELAY
IDLETHERMO
lJ- _iuo'u'j"'
INTAKEAIR DUCT
vaRtousSENSORS
FESONATON
THROTTLEBODY (TB)
1 1-193
www.emanualpro.com

Intake Air System
Air Cleaner
Air Cleaner Eloment Rsplacomsnt
NOTE: Do not clean the air cleaner element by blowingit off with compressed air,
AIR CLEANER ELEMENTNo.mal conditions:Replace air cleaner element every30,000 miles {48,000 km) or 24months whichever comes first.Severe condition3:Replace air cleaner element every15,000 miles 124,000 km) or 12months whichever comes tirst.
m
11-194
Throttle Cable
Inrpection/Adiustmcnt
1. Stan the engine. Hold the engine at 3,000 rpm with noload (in Park or neutral) until the radiator fan comeson, then let it idle.
2. Check that the throttle cable operates smoothly withno binding or sticking. Repair as necessary,
3. Check cable free play at the throttle linkage. Cabtedeflection should be 10- 12 mm (3/8 - 1l2in.l.
'97 - 98 modols:
CABLEBRACKET
LOCKNUT
DEFLECTION10-12mmBIA- 112 i^l
'99 - 0O modsls:
lf deflection is not within specs, loosen the locknut,turn the adjusting nut untilthe deflection is as speci-fied, then retighten the locknut.
With the cable properly adjusted. check the throttlevalve to be sure it opens fully when you push theaccelerator pedal to the floor. Also check the throt-tle valve to be sure it returns to the idle position
whenever you release the accelerator pedal.
DEFLECTIONl0-12mft
Bla - 112 inl
NUT
www.emanualpro.com

Intake Air System
Throttle Body
Doscription
The throttle body is a single-barrel side-draft type. The
lower portion of the throttle valve is heated by engine
coolant from the cylinder head. The idle adjusting screw
which regulates the bypass air is located on the top of
the throttle bodv.
The illustration shows'97 - 98 models,'99 - 00 rnodelsare similar.
1 1-196
lnspection
Check that the throttle cable operates smoothly without
binding or sticking.
lf there are any abnormalities, check for:. Excessive wear or play in the throftle valve shaft.. Sticky or binding throttle lever at the fully closed posi-
tton.
. Clearance between throttle stop screw and throttle
lever at the fully closed position.
97 - 98 models:
THROTTLE LINKAGE
Replace the throttle body if there is excessive play in the
throttle valve shaft or if the shaft is binding or sticking.
THROTTLE LINKAGE
www.emanualpro.com

Intake Air System
Throttle Body (cont'd)
Disassembly
O-RING {A/l only)Replace.
IDLE THERMOVALVE (A/T only)
ADJUSTINGSCREW
9.8 N.m(1.0 kgl.m,7.2 lbf.ftl
The illustration shows'97 - 98models,'99 00 models are similar.
1 1-198
www.emanualpro.com

Positive Grankcase Ventilation (PGVI System
Description
The Positive Crankcase Ventilation (PCV) svstem is
designed to prevent blow-by gas from escaping to the
atmosphere. The PCV valve contains a spring-loaded
plunger, When the engine starts, the plunger in the PCV
valve is lifted in proportion to intake manitold vacuum and
the blow-by gas is drawn directly into the intake manifold.
-: BLOW.BY VAPOR-: FRESH AIR
i/lAlrllFOLD
Inspoction
1. Check the PCV hoses and connections for leaks and
clogging.
'97 - 98 models:
'99 - (X) models:
BREATHERHOSE
(cont'd)
11-201
www.emanualpro.com

Emission Control System
Positive Crankcase Ventilation (PCV) System (cont'dl
2. At idle, make sure there is a clicking sound from the
PCV valve when the hose between the PCV valve
and intake manifold is lightly pinched with your fin-
gers or pliers.
'97 - 98 models:
'99 - 00 modelsi
lf there is no clicking sound, check the PCV valvegrocrmet for cracks or damage, lf the grommet is
OK, reDlace the PCV valve and recheck.
Gently pinch here.
Gently pinch here.
11-202
www.emanualpro.com

EVAP PURGE CONTROL SOLENOID VALVE DUTY CONTROLLED AFTER
STARTING ENGINE
ENGINE COOLANT TEMPERATURE ABOVE 154"F (68'C)
Evaporative Emission (EVAP) Controls
Description:
The evaporative emission controls are designed to minimize the amount of fuel vapor escaping to the atmosphere. The
system consists of the following components:
A. Evaporative Emission (EVAPI Control Canister
An EVAP control canister is used for the temporary storage of fuel vapor until the luel vapor can be purged from the
EVAP control canister into the enqine and burned.
B. Vapor Purge ConirolSystem
EVAP control canister purging is accomplished by drawing fresh air through the EVAP control canister and into a pon
on the intake manifold. The purging vacuum is controlled by the EVAP purge control solenoid valve.
C. Fuel Tank Vapor Control System
When fuel vapor pressure in the fuel tank is higher than the set value of the EVAP two way valve, the valve opens and
regulates the flow ot fuel vapor to the EVAP control canister.
'97 model:
EVAPPURGECONTROL
VALVEFromNo. 15BLK/ /ALTERNATORYEL I sP SENSOR r7.s At(in the under-dashfuse/relay box)
VARIOUSSENSORFEESH AIF
BLK
I
FUEI- TANK
(cont'd)
11-203
INTAKE MANIFOLD
www.emanualpro.com

Description
Rear Differential
Outline
The Real-time 4WD-Dual Pump System model has a hydraulic clutch and a differential mechanism in the rear differential
assembly. Under normal conditions, the vehicle is driven by the front wheels. However, depending on to the driving force
of the front wheels and the road conditions. the system instantly transmits appropriate driving force to the rear wheels
without requiring the driver to switch between 2WD (tront wheel drive) and 4WD (four wheel drive). The switching mecha-
nism between 2WD and 4WD is integrated into the rear differential assembly to make the system light and compact.
ln addition, the dual-pump system switches off the rear-wheel-drive force when braking in a forward gear. This allows the
braking system to work properly on models equipped with an Anti-lock Braking System (ABS).
Construction
The rear differential assembly consists of the torque control differential case assembly and the rear differential carrier
assembly. The torque control differential case assembly consists of the differential clutch assembly, the companion
flange, and the oil pump body assembly. The rear differential carrier assembly consists of the differential mechanism. The
differential drive and driven gears are hypoid gears.
The oil pump body assembly consists of the front oil pump, the rear oil pump, the hydraulic control mechanism, and the
clutch piston. The clutch piston has a disc spring that constantly provides the differential clutch assembly with a preset
torque to Drevent abnormal sound.
The clutch guide in the differential clutch assembly is connected to the propeller shaft via the companion flange, and it
receives the driving force lrom the transfer assembly. The clutch guide rotates the clutch plate and the front oil pump in
the oil pump body.
The clutch hub in the differential clutch assembly has a clutch disc that is splined with the hypoid drive pinion gear. The
hypoid drive gear drives the rear oil pump.
The front and rear oil pumps are trochoidal pumps. The rear oil pump capacity is 2.5 percent larger that the front oil pump
to handle the rotation difference between the front and rear wheels caused by worn front tires and tight corner braking.
The oil pumps are designed so the fluid intake works as a fluid discharge when the oil pumps rotate in reverse. Genuine
Honda CVT fluid is used instead of differential fluid.
Operation
When there is a difference in rotation speed between the front wheels (clutch guide) and rear wheels (hypoid driven gear),
hydraulic pressure from the front and rear oil pumps engages the differential clutch, and drive force from the transler
assembly is applied to the rear wheels.
The hydraulic pressure control mechanism in the oil pump body selects 4WD mode when the vehicle is started abruptly,
or when accelerating in a forward or reverse gear (causing rotation difference between the front and rear wheels). or
when braking in reverse gear {when decelerating). lt switches to 2WD mode when the vehicle is driven at a constant speed
in forwar! or reverse gear (when there is no rotation difference between the front and rear wheels), or when braking in a
fo rwa rd gear (when decelerating).
To protect the system, the differential clutch assembly is lubricated by hydraulic pressure generated by the oil pumps in
both 4WD and 2WD modes. Also, the thermal switch relieves the hydraulic pressure on the clutch piston and cancels 4WD
mode if the temDerature of the differential fluid rises above normal.
www.emanualpro.com