Lack Of Power - Mazda MX-5 1990 Workshop Manual

F
TROUBLESHOOTING GUIDE
• Performance poor under load
• Reduced maximum speed
[TROUBLESHOOTING HINTS]
CD
Factors other than engine malfunction
• Clutch slipping
• Brake dragging
• Low ti re pressu re
• 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 c::::r page H-3
• Brake dragging
IT
page P-27
• Low tire pressure
r:::J'
page
a-3
• Unrecommended tire size c::r page 0-2
LACK OF POWER
@ 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
4
Check switches for correct operation with Self-
Diagnosis Checker Monitor Lamp and ignition
switch ON
F-56
No Check if accelerator cable is correctly
installed
c:7'
page F-9G
~
If OK, check throttle body c::::r page F-94
c::;>
If not OK, install accelerator cable
correctly
r:::J'
page F-9G
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)
c::r page F-80
c::::r page F-128
c::;>
If OK, replace ECU
IT
page F-127
c:>
If not OK, check wiring between
ECU and Self-Diagnosis Checker c::r page F-7
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
1
D
IT
page F-90
and Self-Diagnosis Checker
c:r
page F-7