Hesitates/Stumbles On Acceleration - Mazda MX-5 1990 Workshop Manual

F
TROUBLESHOOTING GUIDE
22 HESITATES/STUMBLES ON ACCELERAT"ION
DESCRIP· • Flat spot occurs just after accelerator depressed or mild jerking occurs during acceleration
TION
[TROUBLESHOOTING HINTS]
CD
Air/Fuel mixture leaning when depressing accelerator
• Fuel injection control malfunction
(Correction for accelerating condition)
• Air leakage of intake air system
• Fuel line pressure Iqw
• Spark advance control malfunction
STEP INSPECTION ACTION
1 Check if "00" is displayed on Self-Diagnosis Yes Go to next step
Checker with ignition switch ON
cr page F-78
No Malfunction Code No. displayed
2
3
Check switches for correct operation with Self-
Diagnosis Checker Monitor Lamp and ignition
switch ON
MONITOR
LAMP "
c:::::r
page F-89
SYSTEM SELECT 1
TEST SW
SELF TEST
~\
Yes
No
Check for cause (Refer to specified
check sequence)
L?
page F-BO
"88" flashes
Check ECU terminal
1
F voltage
c::r page F-128
Voltage; Approx. 12V
(Ignition switch ON)
r:::t> If OK, replace ECU
~ If not OK, check wiring between
ECU and Self-Diagnosis Checker
Go to next step
Lamp not ON/OFF with specified
switch
Check for cause (Refer to specified
c:::::r
page
F-127
cr
page F-7
check sequence)
c:::J
page F-90
Lamp always ON
Check wiring between ECU terminal 1 D
and Self-Diagnosis Checker
c::r page
F-7
Yes Check oxygen sensor
c:::r page F-138
No Go to next step
4 Check if ECU terminal voltages are OK Yes Go to next step
c:::J
page F-128
5 Check if throttle linkage is correctly installed and
operates freely
F-52
r----+------------------------------------------~
No Check for cause (Refer to "Check Point
for Each Terminal")
L?
page F-131
Yes Go to next step
No Correct, clean, or replace as required
any binding or damaged linkage and
adjust cable deflection at throttle body
L?
page F-96