Poor Acceleration - Mazda MX-5 1990 Workshop Manual

F
TROUBLESHOOTING GUIDE
25 POOR ACCELERATION
DESCRIP· • Performance poor while accelerating
TION
[TROUBLESHOOTING HINTS]
CD
Factors other than engine malfunction
·Clutch slipping
• Brake dragging
• Low tire pressure
• Unrecommended tire size
• Overloaded
@ Low intake air amount
• Throttle valve not open fully
• Clogged intake air system
STEP INSPECTION
Check factors other than engine
• Clutch slipping
C7
page
H-~
• Brake dragging c:::r page P-27
• Low tire pressure
r::::r
page Q-3
• Unrecommended tire size
U'
page
0-2
@
Air/Fuel mixture too lean or too rich
• Fuel line pressure low or high
• Insufficient fuel injection
@ Poor ignition
®
Low engine compression
ACTION
Yes Go to next step
No Repair
2 Check if throttle valve fully opens when depress- Yes Go to next step
ing accelerator fully
3
Check if
"00"
is displayed on Self-Diagnosis
Checker with ignition switch ON
U'
page F-78
4 Check switches for correct operation with Self-
Diagnosis Checker Monitor Lamp and ignition
switch ON
F-60
No Check if accelerator cable is correctly
installed
U'
page F-96
¢
If OK, check throttle body
c:::r
page F-94
=>
If not OK, install accelerator cable
correctly
U'
page
F-96
Yes Go to next step
No Malfunction Code No. displayed
Check for cause (Refer to specified
check sequence)
"88" flashes
Check ECU terminal
1
F voltage
Voltage: Approx. 12V
(Ignition switch ON)
=> If OK, replace ECU
c::;>
If not OK, check wiring between
ECU and Self-Diagnosis Checker
Yes Go to next step
No Lamp not
ON/OFF
with specified
switch
Check for cause (Refer to specified
check sequence)
Lamp always ON
Check wiring between ECU terminal 10
c:::r page F-80
c:::r
page F-128
r::::r
page F-127
c:::r page F-7
U'
page F-90
and Self-Diagnosis Checker
c:::r
page
F-7