Valmet 309 - Nozzle Needle Tightness Test; C. DISASSEMBLING, CHECKING AND ASSEMBLING THE INJECTOR

82. Crock I ng
Tesilng rllh a nanual iest
pump
d€s noi
cofrespond to ihe condltlons In the englne and
ihgrgtore
glves
a
rellabla
rgsult only rlih a
ner
nozzle. At a cerfaln
puflplng
speed ihe used
nozzles
have
an
uncreaklng range rhlch
ls
alfected
by the
nozzle
construcflon.
Howsver,
€
qulck
press
should makg the Injector
creak
cleårly
andlor
producE
o flne
spray.
Wlfhln fhe
uncreaklng
range ihe spray ls
rough
and
lrregular.
S5.
Tlghtmss ot fhe nozzl€ n€€dle
Prsss
the tesf
pump
lever slowly
unlll
ihe
gauge
readlng
ls 20 bar b€lo{ the
rated openlng
pressura.
Kgep +he
pressure
ot
thls
level
fo|'
l0 seconds.
lf a drop does not
appear ln the
nozzle llp, tho nozzle tlghtness ls correqt.
Dlsåssemble
a leaklng InJeclor, clean
ihe
seat
surfoces and
perform
a ne{ lesi. lf leaks
appear agaln,
replace
+he
nozzlg.
C.
DISASSEIGLING,
CHES(I IG AND ASSEI,BL It{G I}€
IIIJECTfi
I
45
Parts
ot c Bosch
I nJoqtor
Nozz le
holder
Shlm
Pressure
sprlng
Prsssure
pln
Intermed late
plece
Nozz
le
Nozz le rgtalnlng nui
f. Clean
the nozzles wl+h cleanlng
Jluld froo the
oufslde and the lnslde.
4.
opgn
clogged nozzle
holes
by soaklng and
cle6nlng
needle
(lncludad
In ihe cleanlng
se+
8f60 85288),
948
byö
tool
2.
l. Flx
the lnJec+or to
a screx cl6mp equlpped
pro+ec+l
ve
Jalds.
2.
Opsn the nozzle
retalnlng
nui.
Rgrpve
nozzle
6nd the
pårfs
of fhe
holdgr.
Tesi
the
rDv€iFnf ot
the
nozzlg
n€dlc
cs
tol
lors:
llash +h€ Darts
t{el I rlih
fuel
or fest
fluld.
Puff the needle
out of
tho
body un+ll
l/t
ot
lls slldtng
plane
leng+h
ls
out.
The
needle
shoutd
slld; ttself
back
lnfo
ihs seat.
Repeoi
ihls wlth varlous
needle
posltlons.
Tho
n€edle
måv nof s+lck
In anv
posl+lon.
Recleon
a
sl-icklng
ngzzlg
ond
räPeol
fhe
iesr'
lr
+h€
nozzlo
silll
f€nds
+o stlck'
rapl6ce
lt'
siih
the
g-21