1994 HONDA INTEGRA Workshop Manual

Emission Control System
Three Way Catalytic Converter (TWC) (cont'dl
Inspection
lf sxcessive oxhaust system back-pressure is suspected. remove the TWC trom the car and make a visual check for plug-
ging, melting or cracking of ths catalyst. Replace the TWC if any of the visible area is damaged or plugged.
81881 ongino:
TI{REE WAYCATALYTICCONVERTER {TWCIRemovsl/installation, see section 9
Inspect housing for cracks orother damage.Inspect element tor cloggingby looking through the inside.
HEAT SHIELD
11-132
T SHIELO

818Cl engine:
HEAT SHIELO
r{
THREE WAYCATALYTICCOI{VEBTEB {TWCIR€moval/installation. sso s€ction 9Inspoct housing tor cracks orothor damage.Inspect elemont for cloggingby looking through the inside.
HEAT SHIELD
11-133

Emission Control System
Positive Crankcase Ventilation (PCVI System
Description
The Positive Crankcase Ventilation (PCV) system is
designed to prevent blow-by gas {rom escaping to the
atmosphsre. The PCV valve contains a spring-loadsd
plunger. When the Bngine starts, the plunger in the PCV
valve is lifted in proportion to intake manifold vacuum
and the blow-by gas is drawn directly into th€ intak€
manifold.
FCV VALVE
.F: ILOW-BY VAFORer FRESH AIR
11-134
Insp€cdon
1. Check th€ PCV hos6s and connections tor lsaks and
clogging.
At idle, mak6 sur€ th6fe is a clicking sound from th6
PCV valve when the hose between rcV valve and
intake manifold in lightly pinched with your fingors
or oli€rs.
a lf thera is no clicking sound, ch6ck the PCV valve
grommet for cracks or damage. ll the grommet
is OK, reolace the PCV valve and recheck.
2.
SREATHER
Gontly pinch hero.

A.
Evaporative Emission (EVAPI Controls
Da.cdptlon
Thg avaporstive omission controls are designed to minimize the smount of fusl vapor escaping to the atmosphero. The
system conaists ot the following compon€nts:
Evlporttly. Emlttbn (EVAPI Control Caniltot
An EVAP control canistor is used lor the temporary storage ot fuel vapor until the fuel vapor can be purged lrom
th€ EVAP control canister into the engin€ and burned.
vlpor hr]gG Cmt]ol Syst m
€VAp control canistgr puroing is accomplished by drawing fresh air through tho EVAP control canister and into a
pon on th6 throttl€ body. Th€ purging vacuum is controllsd by the EVAP purge control diaphragm valve end the
EVAP purge control solenoid valve.
C. Ft|.l Tmk Vlpor Control Systom
When fuel vapor prassure in the fuel tank is higher than the set v8lue of the EVAP two way v8lv6, th€ valve opens
and regulates the flow ol fuel vapor to the EVAP control canister.
(cont'd)
11-135

Emission Gontrol System
Evaporative Emission (EVAPI Control (cont'd)
EVAPTWO WAY VALVE
EVAPPURGECONTROLSOLENOIDVALVEFUEL TANKEVAP VALVE
FUELFILL CAPVARIOUSsEt{soRs
BLK
5
EVAP CONTROLCANISTEB
FRESHAIR
11-136

#7 VACUUM HOSE
Troublclhooting
VACUUM PUMP/GAUGEA973X-O41-XXXXX
EVAP PTJBGE COI{TROLDIAPHRAGM VALVE
EVAPPUBGE CONTROL
Bl8Bl .noin.:YEL/BLK I+I
(-t
wirg aide
--\
EVAPR'RGE COI{TROLSOLENOID VALVE
(cont'd)
VALVE
YEL/BLK (+I
Disconn€ct #7 vacuum hose
trom the EVAP putgo control di'
aph.agm valve lon the EVAPcon-
t.ol canistor) and connoct a
vacuum gauge to tho hose.
Stsrt the €ngine and allow it toidls.NOTE: Engine coolant tempera-
ture must be b€low 163oF (73ocl
Oisconnect the 2P connegtor trom
the EVAP purge control solenoid
Mea suro voltago betw€enYEL/BLK {+) terminsl 6nd RED
l-) terminal.
Inapact vacuum hoa€ror.ring.l| OK, toolrc. EVAPpurgo conttol solenoidls ther6 battery voltage?
Moasule voltage botweenYEL/BLK {+) terminal bodYground.
(To pa96 1 1- 138)
(To page 1 'l -139)
11-137

(From page 1 1-137)
lTo page 1 1-'l39)
Start the engine. Hold the engineat 3,OOO rom with no load lA/T in
E orE position, M/T in neutrsl)unlil lhe radiator tan comes on.then let it idle.
Check lor vacuum at # 7 vacuumhose alter starting the engine.
Oisconnect the 2P connoctor fromthe EVAP purge control solenoid
Intpoct vacuum hoaarcuting.It OK, reolrco tr|c EVAP
Purge contlol lolanoid
ls there manifold vacuum?
Inrpoct for a short i|t RED wire bo-lwoen ECM {A2Ol and th6 con-noclor.ll wiro la OK, substituto a known-good ECM 6nd .echock. lf symp-tom goes away, loplace tho origi-nal ECM.
Ropair opon in YEL/BLKwirc b.tw..n EVAPpurgo control rolanoidvrlvo and th. xiM-Flmlin r6lay.
ls there baftery voltage?
Inspoct RED wirc for 6n opon totrody g.ound botween ECM lA20)and th6 conn6ctor.It wir. b OK, substiluto a known-good ECM and rochock, It sym-ptom 9o6s away, roplaco thooriginal ECM,
Emission Gontrol System
Evaporative Emission (EVAP) Gontrols (cont'd)
{From page 11-137}
11-138

(F.om pdge 1l-138)
Connoct a vlcuum gaugo tocaniator purg! lir ho!o.
Stsn tho onginc lnd rai!. spo€dto 3,50O rpm.
Connect a vacuum gauge to thecsnister puag6 hos6 and raise thesngin€ spe€d to 3,500 rpm.
Do€a vocuum opp€ar on gougo
within 'l minuto?
Saa EVAP tso {ay vdv. t.!t ioconrDbta.Evapoardva ambdon coartaoL |.|ox.
Inapoct tha purga hosoand drronl. body potl
for pinch or blocklga.
VACUUM PRESSUREGAUGE O-4 In.HgoTJAZ-OOIOOOB
PURGE AIR HOSE
(cont'd)
11-139