check engine NISSAN 300ZX 1984 Z31 Automatic Transmission Workshop Manual

REMOVAL AND INSTALLATION
installation (Cont'd)
Check inhibitor switch for operation
Check fluid level
in transmission.
Move selector lever through
all positions to be
sure that transmission operates correctly.
With parking brake applied, rotate engine
at
idling Move selector lever through "N" to
"D", to "2". to "1" and to "R" A slight shock
should
be felt by hand gripping selector each
time transmission
is shifted.
Check to be sure
that line pressure is correct.
To do this, refer to Line Pressure Test
Perform stall test.
AT-I 9,

TROUBLE-SHOOTING AND DIAGNOSES
Preliminary Checks
(Prior to Road Testing)
FLUID LEAKAGE
To detect a fluid leak
1) Raise vehicle
2) Clean area suspected of leaking
3) Start engine, apply foot brake, place control
lever in drive, and wait a few minutes
4) Stop engine
5) Check for fresh leakage
FLUID CONDITION
Examine the AT F and note its color, texture,
and odor
1) Dark of Black Fluid
With a burned odor
- Worn friction material
2) Milky Pink Fluid Water Contamination
- Road water entering through filler
tube or breather
3) Varnished Fluid, light to dark brown and
tacky Oxidation
- Over or Underfilling
- Overheating
- Road Testing
Before starting road tests, install vacuum gauge
SAT596
Perform road tests, using "Symptom" chart, as
follows
"P" RANGE
1 Place the control lever in "P" range and start
the engine Stop the engine and repeat the
procedure in all other ranges and neutral
2. Stop vehicle on a slight upgrade and place con-
trol lever
in "P" range Release parking brake
to make sure vehicle remains locked
"R" RANGE
1 Manually shift the control lever from "P" to
"R", and note shift quality
2 Drive the vehicle in reverse long enough to
detect slippage or other abnormalities
"M" RANGE
1 Manually shift the control lever from "R" and
"D"
to "N" and note quality.
2. Release parking brake with control lever in
"N" range Lightly depress accelerator pedal to
make sure vehicle does not move (When
vehicle
is new or soon after clutches have been
replaced, vehicle may move slightly This
IS not
a problem )
"D" RANGE
1 Manually shift the gear selector from "N" to
"D" range, and note shift quality.
-
AT-63

TROUBLE-SHOOTING AND DIAGNOSES
Road Test
2 Using the shift schedule as a reference, drive
vehicle in
"D" range Record, on symptom
chart, respective vehicle speeds
at which up-
shifting and downshifting occur These speeds
are to be read at several different intake mani-
fold vacuum levels
(see the chart on the next
page). Also determine the timing
at which
shocks are encountered during shifting and
which clutches
are engaged
Drive on different throttle condirtom
SAT590
3. Check to determine if shifting speed changes
when accelerator pedal
is depressed slowly and
when
it is depressed quickly (E4N71B trans-
mission models)
4 Check to determine if shifting to overdrive gear
cannot be made while power shift switch
(E4N71B transmission) is"0N" or
O.D. cancel
switch (4N71
B transmission) is "OFF".
0 0. cancel witch SAT744
3 (Cont'd)
5. When vehicle is being driven in the 65 to 85
km/h (40 to 53 MPH) range in "Ds" range at
half to light throttle position, fully depress ac-
celerator pedal to make sure
it downshifts from
3rd to 2nd
gear.
6. When vehicle is being driven in the 25 to 35
km/h (16 to 22 MPH) ("D," range) at half to
light throttle position, fully depress accelerator
pedal to make sure
it downshifts from 2nd to
1 st gear
"2" RANGE
1 While vehicle is being driven in "2" range,
make sure that
it does not shift into 1st or 3rd
gear, despite speed changes.
2 Shift control lever to "D" range and allow
vehicle to operate
at 40 to 50 km/h (25 to 31
MPH) Then, shift to "2" range to make sure
it downshifts to 2nd gear.
"1" RANGE
1. Shift control lever to "1" range and allow
vehicle to run. Ensure
that it does not upshift
from 1st to 2nd gear although vehicle speed
increases
2 While vehicle is being driven in "1" range,
release accelerator pedal
to make sure that
engine compression acts
as a brake
3. Shift control lever to "D" or "2" range and
allow vehicle to run
at 20 to 30 km/h (12 to 19
MPH). Then, shift control lever to "1" range to
make sure the downshift to 1st gear is made.
AT-64

TROUBLE-SHOOTING AND DIAGNOSES
Pressure Testing (Cont'd)
Intake manifold
vacuum
kPa (mmHg,
inHsl
VG30E engine without turbo
Propeller $haft
Vehicle speed revolutions
kmlh (MPH)
rpm
Range I Line pressure kPa (kglcm', psi)
Intake manifold
vacuum
kPa (mrnHg.
inHg) ~
R I 1,961 - 2,393
(20 0.24 4,284 .347)
Propeller shaft Vehicle speed
kmlh (MPH) revolutions
rpm
D I 1.079-1,226(110-125,156-178)
2 I 1,079 - 1,275 (11 0.13 0, 156 - 185)
1 I 1,079 - 1,226 (1 1 0 - 12 5, 156 - 178)
VG30E turbo engine
Range I Line pressure kPa (kgtcm', psi)
R I 1,961 - 2,354 (20 0 - 24 0,284 - 341)
D I 1,667 - 1,883 (17 0- 19 2,242 -273)
2 I 1.667-1,883(170-192,242-273)
1 I 1.667-1.8831170-192.242-273)
Judgment by measuring line pressure
If line pressure does not rise, first check to make
sure that vacuum
hose is connected properly.
1) When line pressure is low at all positions, the
problem may be due to
Wear on interior of oil pump
Oil leakage at or around oil pump, control
valve body, transmission case or governor
Sticking pressure regulator valve
Sticking pressure modifier valve
2) When line pressure is low at a particular posi-
tion, the problem may be due to the following
If oil leaks at or around forward clutch (rear)
or governor, line pressure
is low in "D", "2" or
"1" range but is normal in "R" range.
If oil leaks at or around low and reverse brake
circuit, line pressure becomes low in
"R" or
"P" range but IS normal in "D", "2" or "1"
range.
3) When line pressure is high, pressure regulator
valve may have stuck
Cutdown point
The cut-down point indicates
a point where line
pressure changes from high to low value.
Before proceeding cut-down testing, make sure
that line pressure "At Idle" and "At
Stall'' is
normal
Install vacuum gauge
VG30E engine without turbo
28 - 37
o(o'o) I (17-231 I 900- 1,200
12.22
(7 - 14) I 400-700 (-100. -133 -3 94) I
VG30E turbo engine
+467 I 29 - 39 1,200- 1,600 (+350, +13 78) (18 - 24)
13.23
(-200,
-267 -7 871 I (8. 14) 400 - 800
Judgment by cut-down testing
(1) When cut-down point disappears, the problem
Sticking pressure modifier valve
Sticking governor valve
Oil leaks at oil passage
(2) When cut-down point is too low or too high,
the problem may be due to
Incorrect springs (at pressure modifier valve
or governor valve)
Oil leaks at oil passage
may be due to
AT-92

TROUBLE-SHOOTING AND DIAGNOSES
Stall
The stall test is an effective method of testing
clutch and band holding ability, torque converter
one-way clutch operation, and engine performance
A
stall test should only be performed as a last
resort because of the high fluid temperature it
generates and the excessive load it places on the
engine and transmission.
CAUTION:
a. Transmission and engine fluid levels should
b
c.
d
always be checked and fluid added as needed.
Run engine to
attain proper warm-up.
During test, never
hold throttle wide-open for
more than
5 seconds
Do not test more than two gear ranges without
driving vehicle to
cool off engine and trans-
mission
STALL TEST PROCEDURE
1 Set parking brake and block wheels
SAT597
2 Install a tachometer where it can be seen by
driver during
test
3 Start engine and place select lever in "D"
range
4 Apply foot brake and accelerate to wide-open
throttle
5 Quickly note the engine stall speed and imme-
diately release throttle
Stall revolution:
VG30E engine without turbo
VG30E turbo engine
2,150 - 2,450 rpm
2,500 - 2,800 rpm
SAT598
6
7 CooloffAT F
8 Perform stall tests in the same manner as in
steps 3 through 7 with select lever in "1" and
"R", respectively
Shift select lever to "N"
AT-93