Rough Idle With Warm Engine - Toyota 3b Repair Manual

ROUGH IDLE WITH
WARM
ENGINE
(Possible Gause)
(Check Procedure and Correction Method)
1.
IMPROPER ADJUSTMENT OF
ACCELERATOR CABLE
With the accelerator pedal released, check that the
adjusting lever is in contact with the idle adjusting
screw. Also, check if the accelerator cable
ii
catciing
on something.
lf
necessary, adjust so lever is in contact
with the
screw, or make other required repairs.
2.
IDLE SPEED TOO LOW
Check the
idle
speed as
specified below.
(See page EM-25)
ldle
speed:
M/T
600
-
7OO
rpm
A/T
77O
_
g2O rpm
lf
not, adjust with the
idle adjusting screw.
HINT:
lf
less
then specified, idling would normally
be rough.
Check
for leaks in the injection pump connections,
pump distributive head bolt,
nozzle holder and
delivery
valve.
Tighten any
loose
connections to specified torque or
replace parts as
necessary.
4.
IMPROPER TNJECTION
TIMING
REfCr
tO
itEM 9
Of
ENGINE CRANKS
NORMALLY
BUT
WILL
NOT START, above.
5.
IMPROPER OPERATION OF
INJECTION
NOZZLE OR
DELIVERY VALVE
With the engine idling, loosen the injection pipe to
each cylinder in order, and check if the idle
speed
changes.
lf
no change,
a
faulty cylinder is indicated.
Check
according to the following procedure.
o
Faulty
Nozzle
Check the
nozzle
with
nozzle
tester.
(See
page FU-9
or
1S)
Opening pressure:
Band
38
1OS
-
12Skg/cmz
(1,493
_
1,778 psil
(10,296
_
12,258kPa\
11Band
148 180-
21Okg/cmz
(2,560
_
2,987
psi)
(17,652
_
20.594
kpa)
lf
not
within
specification, the
nozzle is faulty and
injection pressure should be readjusted.
o
Faulty Delivery Valve
lf injection pressure
is
within
specification, the
delivery valve
is defective and should be
replaced.