Fuel And Emission Control System Troubleshooting (Turbo); Troubleshooting Guide - Mazda 626 MX-6 Workshop Manual

4B

TROUBLESHOOTING GUIDE

TROUBLESHOOTING GUIDE
This troubleshooting guide shows the malfunction numbers and the symptoms of various failures.
Perform troubleshooting as described below.
Possible cause
Symptom
Fault Indicated by SST
Code No.
Hard start or won't start
(Cranks OK)
While warming up
Engine
stalls
After warming up
Rough While warming up
idle
After warming up
High idle speed after
warming up
Poor acceleration, hesita­
tion or lack of power
7 Runs rough on deceleration
Afterburn in exhaust system
8
Poor fuel consumption
9
Excessive oil consumption
10
Engine stalls or rough af­
11
ter hot starting
12 Knocking
13 Abnormal noise or vibration
14 Fails emission test
4B—8
Input sensors and switches
a
c
o >
' 3 5
T ~
o
o>
4B 4B 4B 4B 4B 4B 4B
I I I I I I
I
17 18 19
16 20 21 22
01 02 03 04 05 08 09 10
TROUBLESHOOTING PROCEDURE
Note
Step 1 under symptom is to quickly determine what system or unit
may be at fault by use of the SST. (Self-Diagnosis Checker 49 H018
9A1)
1st: Check input sensors and output solenoid valves with the SST. (Refer to
page 4B—11.)
2nd: Check other switches with the SST. (Refer to page 4B—33.)
3rd: Check the following items:
Electrical system
1) Battery condition
2) Fuses
Fuel system
1)Fuel level
2) Fuel leakage
3) Fuel filter
4) Idle speed (with test connec­
tor grounded)
Engine
1) Compression
2) Overheating
4th: Check Fuel and Emission Control Systems. (Refer to page 4B—9.)
Output solenoid valves
«
JC
a.
w
&
O
O C
E
o
UJ
4B
4B 4B 4B 4B 4B 4B
I
I I I
I I
I
23 24 25 26 27 28 29
14 15 16 17 25 26 28 29 34 42
12
Ignition system
1) Ignition spark
2) Ignition timing (with test connec­
tor grounded)
Intake air system
1) Air cleaner element
2) Vacuum or air leakage
3) Vacuum hose routing
4) Accelerator cable
Others
1) Clutch slippage
2) Brake dragging
a.
M
2
a >
>
< o
>
■ o
o
c
a >
o
tn
4B 4B 4B 4B 4B
I I
I I I
29 30 30 31 31
86U04B-003