Diesel Engine Diagnosis; Preliminary Checks - Toyota 3b Repair Manual

EM-4
ENGINE MECHANICAL
-
Diesel Engine Diagnosis
DIESEL ENGINE
DIAGNOSIS
1.
GENERAL
Diesel engine problems are usually caused by
the
engine or
fuel
system. The injection pump is very
rarely the cause of fuel system problems.
Before beginning fuel system tests,
first check that the engine compression, valve timing and other major
systems are
within
specifications.
2.
PRELIMINARY CHECKS
(a)
Before performing fuel
system checks, insure
that the
engine
is in
good running condition. lf
necessary,
first check the compression,
timing
and major components or systems.
(b)
Check
the air filter and clean or replace as
necessary.
(c)
Check
for sufficient fuel in the tank.
(d)
Check
if the fuel is contaminated with gasoline or other foreign elements. Only high-quality
diesel
fuel should be
used.
(e)
Bleed
air from the system
by
pumping the priming pump.
(f)
Check
for water in the sedimenter and fuel tank, and drain as necessary.
(g)
lf the engine
will
not crank or
if
it cranks slowly, troubleshoot the electrical system.