S-4 Engine Startability Is Poor - Komatsu PC88MR-10 Shop Manual

40 Troubleshooting
Troubleshooting of engine (S-mode)

S-4 Engine startability is poor

Engine startability is poor.
Failure
If any failure code is displayed, perform troubleshooting for that code first.
Common rail fuel injection system (CRI) controls fuel injection timing electrically.
Related
Therefore, in some cases, engine does not start before crankshaft makes 2 turns
information
maximum even if starting operation is performed. This does not indicate any abnormality,
however.
No. Cause
Defective battery
1
2 Insufficient fuel in tank
Improper fuel used
3
Clogged air breather hole in
4
fuel tank cap
Clogged fuel filter element
5
Foreign material in fuel
6
Air in fuel piping system
7
Leakage from fuel piping
8
system
Defective supply pump
9
10 Clogged air cleaner element
11 Defective intake air heater
Cracked EGR cooler
12
(Reference: Coolant enters
exhaust gas piping.)
13 Defective injector
14 Defective engine controller
40-518
(D37-A10-400-A-Z0-A)
Point to check, remarks
Specific gravity of electrolyte and voltage of
battery are low.
Fuel tank is empty.
Fuel other than specified one is used.
Fuel used does not accord with ambient
temperature.
(Reference: If engine can start in warm
weather but does not easily start in cold
weather)
Deposited wax (milky) is found in clear bowl
of fuel prefilter.
Air breather hole in fuel tank cap is clogged.
Check used hours of fuel filter. If used
beyond specified hours, fuel filter element
may be clogged.
Rust and water are found in fuel drained
from fuel tank.
Air is bled during air bleeding of fuel system.
(Reference: See Testing and adjusting,
"Bleeding air from fuel system".)
Fuel leaks from fuel piping.
(Reference: See Testing and adjusting,
"Testing fuel circuit for leakage".)
See Testing and adjusting, "Testing fuel
discharge, return and leakage".
Air cleaner dust indicator indicates that dust
is at caution level.
When preheating works, intake air heater
mounting area does not become hot.
When preheating works or when
temperature is low, preheating monitor does
not indicate properly.
Remove exhaust gas piping from EGR
cooler outlet and inlet, and check whether
coolant containing COOLANT flows out.
a Water in exhaust gas can be normally
condensed, so check that condensate is
coolant or not.
Some cylinder is found to be cool when
exhaust manifolds are touched by hand
immediately after engine is started.
When engine is run in cylinder cutout mode
with some cylinder cut out, engine speed
does not change.
(Reference: See Testing and adjusting,
"Handling cylinder cutout mode operation".)
Since this is an internal defect,
troubleshooting cannot be performed.
Remedy
Add battery electrolyte
and charge battery.
Add fuel.
Use proper fuel
specified in Operation
and Maintenance
Manual.
Flush air breather hole
in fuel tank cap and
clean surrounding
area.
Replace fuel filter
element.
Replace fuel.
Perform air bleeding.
Repair or replace fuel
piping.
Repair or replace fuel
piping related parts.
Replace supply pump
or pressure limiter.
Check and clean air
cleaner element.
Replace intake air
heater.
Replace EGR cooler
and drain water from
engine cylinders
Replace injector.
Replace engine
controller.
PC88MR-10