Engine Stalls During Start-Up - Mazda MX-5 1990 Workshop Manual

I _
F
TROUBLESHOOTING GUIDE
ENGINE STALLS DURING START-UP
- Engine unexpectedly stops running while starting
[TROUBLESHOOTING HINTS]
CD
Misfire occurs when depressing accelerator
• Air/Fuel mixture too rich or too lean
-Incorrect ignition timing
- Weak ignition
STEP
INSPECTION
Check if brakes are dragging
c::r
page P-29
2
3 Check switches for correct operation with Self-
Diagnosis Checker Monitor Lamp and ignition
switch ON
c::::t
page F-89
@ Lack of engine torque for start-up
• Air/Fuel mixture too rich or too lean
- Low intake air amount
• Low engine compression
ACTION
Yes Repair
No Go to next step
No Go to next step
No
Malfunction Code No. displayed
Check for cause (Refer to specified
check sequence)
"aa"
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 1 D
c::r
page P-29
c::r
page F-78
c::r
page F-128
c:::r page F-127
c::r
page F-7
c::::t
page F-90
and Self-Diagnosis Checker
c:::r page F-7
4 Yes Check oxygen sensor
c::r
page F-138
No Go to next step
5 Check if ECU terminal voltages are OK Yes Go to next step
c::r
page F-128
No Check for cause (Refer to "Check Point
for Each Terminal")
c:::r
page F-131
F-46