Yanmar 4LHA-HTP Operation Manual page 464

Chapter 3 Fuel Injection Equipment
6. Fuel Feed Pump
6 - 5 Fuel Feed P u m p A d j u s t m e n t
1. Testing procedures f o r the fuel feed pump
Set the fuel feed p u m p on the injection pump, and
operate the assembled u n i t on the pump tester.
Fuel piping should be provided directly from the tank,
not through the delivery pump of the tester.
(1) Suction test for the priming pump
Loosen the handle o f the priming pump, and push
the handle at 60 — 100 strokes/minute. If fuel
comes out of the delivery side of the feed pump
after about 30 strokes, the priming pump is normal.
If it takes longer, replace the priming pump as a
set.
Suction head
Suction pipe dia.
O
Valve (B)
E q u i p m e n t for feed p u m p test
1 m
W i t h i n 3 0 s t r o k e s
Pressure gauge
0 - 0.98(10)MPa(kgf/cin)
Valve ( A ) .
Feed pump
3-2-42
(2) Max. delivery feed volume test
Y o u will need the special equipment for conduct-
ing max. delivery pressure and delivery volume
tests.
M a x . delivery pressure test
NOTE: 1. Do not run the equipment
5 minutes since the fuel injection
may be damaged if
injection condition.
2. Operate the injection
fied rpm, and read the pressure gauge
indicator when
completely.
pressure gauge indicator
when the pressure is applied.
> Volume pressure[MPa(kgf/cm')]:0.216-0.314(2.2-3.2)
• rpm:600
Replace the piston spring if it is defective.
(3) Delivery test
Operate the fuel injection p u m p at the specified
r p m , open valve (B) until the pressure gauge
indicator s h o w s
measure the delivery rate for one minute.
• V o l u m e ( t /min.): over 1.8
• Back pressure (MPa(kgf/cm')] :0.098(1)
» r p m : 1000
Delivery test
4LHA Seriesy
for more than
pump
operated in
pump at the speci-
valve B is tightened
Tighten valve A so that the
does not move
0.098(1 )MPa(kgf/cm),
non-
and