Technical data
COMPLETE CAR
a. Disconnect pipe 8
0
from dump
valve 9
n
CHECK ON AIR SUPPLY
SISTEM
TIGHTNESS
DOWNSTREAM FROM THE
AIR
FLOW SENSOR
This procedure is for electronic injec-
tion 1.7
engines
with catalytic
con-
vertor
0nly.i
Makesurethatallpipefixingclampsare
fully,tightened
b. Warm engine up to normal run-
ning speed.
nected.
air source to the
with a gauge
con-
c. Disconnect ignition.
d. Effect a visual check. of fuel
system components and fittings in
order to locate leak origin.
b. Pressurize the system with
compressed air to reach a pressure of.
e. Check the whole system
(connect-
ing pipes, fittings, components) using
a gas detector.
2.49
KPa
(0.025 bars;
0.0255 Kg/cm2; 254 mm
HzO)
Start engine at idle r.p.m., then
manu-
ally
deform;
pipings#and
sleeve
down-
stream
from
the air flow
sensor
Should
,the’re
be
any
faulty pipes with
air inlets to ‘engine undetected by
sensor, some variations of idle r.p.m.
Will take place
TO
ease’the
location of
any
possible
leaks in the air supply system, spread
some
suds
on involved pipes.
f.
Close to leak area,
one
Will
note
a tester pointer
reaction.
and then close the
connection.
If
one
cari’‘’ (reach the specified value,
open
the compressed air supply system
and check the system tightness (with
gas deteetor).
. . .
This test with tester must be effected
slowly in order to compensate for
the time delay of tester response.
c. Measure pressure drop in system
(it must not iexceed
_,_<-
9.
Following leak location, follow
procedure steps d.
and/or
e. then
eliminatethe
leakreplacingfaultycom-
ponents or properly tightening
loosen-
ed
clamps.
.h
0.125
KPa
(0.00125 bars;
0.0127
K&cm2;
12.7 mm
Hz0
TROUBLiZ?HOOTING
PROCED~URE TO CHECK FUEL
$UPPLi/
FYSTEM TIGHTNESS
h. On completion of operation, start
the engine letting it idle run for few
(
minutes and then switch ignition off.
in’ 10 minutes).
This procedure is valid for electronic
injection
i
-78
engines with catalytic
convertor
pnly.
d. If within 10 minutes the pressure
drop exceéds this value, locate leak
spreading pipes with suds or using
gas
detectorl
i.
Repeat test as per steps c. and
d.
to check that diagnosis is correct and
repair is efficient.
This procedure is to be effected when
reaching the km stated on “Chart of
Vehicle
Ma,intenance
Operations”,and
if the
foll,owing
symptoms occur:
-
Petroli
smell.
1.
At end of whole procedure, road
test for
about
30 minutes and then
make a final test to be sure of system
integrity.
e. When there are leaks, some soap
bubbles
Will,
appear.
f. Should the leak corne from
fuelcap
filling union
area,
first replace the cap.
If after replacing cap, tightness is
re-
stored, this
means
that cap was faulty,
otherwise replace the union.
TROUBLESHQOTING
PROC.EDURE
TO CHECK FUEL
VAPOUR EMISSIONS
CHECKING SYSTEM
TIGHTNESS
-
Visual signs of leaks from system
fittings and connections.
g. Replace faulty components or
tighten loosened clamps.
h. Repeat procedure b. and c. to
check diagnosis efficiency.
-
Effectithe procedure stated in
para-
.graph”FuelEngine-CheckonFuel
Supply
,Pressure
and Circuit
Tightness”
-
steps 1. and 2..
completing it with what follows:
1.
If after effecting the above
men-
tioned process, leaks still exist,
effect
diagnostic procedure to check the
supply system tightness of fuel in-
jection system.
Possible causes could be:
a.
Make’
sure
that
fire-fighting
-
Leaks of vapour from system
applicances are available in order tobe
components, accessories and
able to operate safely.
connections.
May.
1988 ~
i
PA333500883300
00-18