Perkins L4 Workshop Manual - L-36 Fleet

Page S6 Fue/ Injection System-continued
THE FILTERS - See Section G.
LIFTPUMP.
Tbe inlet valve of the lift pump is accessible
af ter removal of the hand primer. Tbe outlet
valve is under the plug T, Fig. S.I. The$e valves
and their seats must he perfectly clean.
Tbe following are possible troubles with the lift
pump and the way in which they can he remedied.
1. Lift Pump does not deüver FueL
Condition or suggestcd
Possiblc Causc location rcmedy for correct
working
(a) Fuel tank Fuel tank. Must contain an adeempty.
quate supply.
(b) Fuel cock Fuel cock. Must be open to iu
closed. ruIl extent.
(c) Preliminary Preliminary filter Remove by loosening
filter choked. gauze P. round nut Q and lifting
fixing strap R.
Wash in clean fuel
,lil or paraffin. Ir
damaged. replace.
fake care to repJace
washer S.
(d) Inlet or Valves F. & H. Remove by unscrewing
outlet valve! hexagon plug T, and
fouJed or primer Z. Clean in
damaged. fuel oil or paraffin.
Take care to screw
plug Tand primer. Z,
in to the full e~tent
when replacing.
(e) Plunger or Plunger L and E.~tract after unscrew.
tappet spin- tappet spindIe jng cap V. Oean in
dIe fouled N. fuel oil or paraffin.
or damaged.
NOTE : If damaged, return
complete with body to
nearest authorised
agent.
2. Lüt Pump does oot deüver Sufficient Fuel.
- Condition or suggested
Possible Cause Location remedy for correct
working.
(a) Connection
or pipes beo
tween the
lift pump
and Cuel
pump teak.
Connection pipe. Sec that aJI joints and
pipes are perfectly air-
tight.
ing.
(b) !nIet or out-
Iet valves
Yalves F. & H. rreat as for (d).
leaking.
(c) Plunger Plunger L. Treat as ror 1 (0).
leaking.
(d) Plunger
spring
Plunger
spring G.
Replace.
darnaged.
(e) Preliminary
filter ob-
.trn~d.
Preliminary
filter
Gg1l7~ P
CARE OF THE INJEcnON EQUIPMENT.
Condition or suggcsted
Possible Cause Location. rcmcdy for correct
...
working.
(f) Main pipe
line filter
obstructed.
(a) Air locked
system.
Main filter. Llean and vent air as
i nstrUcted (In this page.
Main filter.
Air Venting the Foei System.
Vent air by opening
vent screw on main
filter and allowing fue!
(0 flow until perfectly
free from bubblcs. See
below.
If tbe fuel system bas been opened at any time,
sar for au overhaul, it is necessary to ensure that
all air bas been removed before attempting to
start the engine. This should he done as follows :
Pressure Fed Systems.
Slacken small plug on the top of final filter
and operate the hand primer on the fuel lift
pump until Cue! free from air bubb!es issues from
the plug hole. Tighten the plug.
Slacken tbe bleed cock on the top of the fuel
pump.
Again operate the hand primer on the fuel lift
pump unti! fuel issues from the bleed cock and all
signs of air have disappeared.
Tighten the b!eed cock securely and give the
primer a few more strokes in order to deliver tbe
Cue! througb the relief valve on tbe final filter
clearing this part of thc systcm of air.
Gravity Fed Systems.
Slacken small plug on the top of the final filter
and turn on fuel tank supply tap until fuel free
from air bubbles issues from the plug hole.
Tighten the plug.
Slacken the bleed cock on the top of the fuel
pump and allow fuel to run until no trace of air
remains.
Tighten the bleed cock securely whilst fuel is
still issuing.
ENGINE TROUBLES
Treat as for 1 (c). Fuel injection difficulties can arise on the engine
from several causes. some of which mav he traced
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