Yanmar 2GM - Page 39

TRO UBLESHOO TI NG
CURRENT OUTPUT TEST
35A ALTERNATOR
Battery cable
33
z
55A ALTERNATOR
Ammet er
Battery
cable
,VOTE
If the fuel injection pump or a fuel injectoris
suspected. haw' it checked by a diesel en-
gine serv ice shop before purchasing re-
placement parts.
When troubleshooting the fuel system. ref er to the fol-
lowing symptoms and possible causes:
1. Engine will not sl art-e hcck for an empty fuel lank,
incorrect fuel or water in the fuel. Bleed the fuel system as
described in
Chapter Seven to besure that fuel is rout ed to
the fuel in
je ction pump and to locate any restrictions. such
as the fuel filter,
or defective compone nts, such as the fuel
transfer pump.
Check for properoperation and adjustment
of the speed control mechanism. including the stop lever.
Refer to Chapter Seven. Check the fuel injection timing as
directed in Chapter Seven.
2. Engine slops suddenl y-C hcck for an empty fuel tank,
incorrect fuel or watcr in the fuel. Bleed the fuel systcm as
directed in
Chapter Seven to be sure that fuel is routed to
the fuel injection
pump and to locate any restrictions, such
as the fuel filter,
or defective compo nents, such as the fuel
transfer pump. Check for thc proper operation and adjust.
rnent of the speed control
mecha nism , including the stop
lever.
3. Engine speeddecreases unexpectedly--Check for wa-
tcr in the fuel. Check for a clogged fuel filter element.
Bleed the fuel system as described in Chapter Seven to
reo
move air in the fuel. Check for clogged or def ecti ve fuel
in jec tion pump or fuel injector.
4. Engine will not run under fu ll loa d-e heck for a
clo
gged fuel filter element. Che ck for a defective fucl
transfer pump. Check for a clogged
or defective fuel in-
jec tion pump. Check the speed control mechanism.
5. Engine misfires -C heck for water in the fuel. Check
for a clogged fuel filter clement. Bleed the fuel system as