Mazda 121 - Rough Idle;Engine Stalls at Idle - before Warm-Up

TROUBLESHOOTING
GUIDE
F
9
ROUGH IDLE./EI{GINE STALLS
AT IDLE
_
BEFORE
WARM.UP
OESCRIP-
I
.Engine
speed low or engine stalls or vibrates
excessvely al
idle
durlng
warm_up
Ttolt l
frRouBLESHOOT|i,rG
HTNTSI
O
Low lntake ar amount
.Carbon
deposil ln
injection
body
.Aif
cleaner
element c ogged
.
Thefiowax
unil sluck
O
Low
fue njectiof control
.Fuel
njection control maifunclion
(Coiiection
for
coolanl
temperalure)
@
Poor alornization
.Low
BvP
(summe0
fuel used
in
cold
wealher
INSPECTION
ACTION
1 ls
"00 '
displayed on Self Diagnosis
Checker
wilh igniton switch ON?
F
page
F-67
TEST SW: SELF TESI
Malfunction Code No. displayed
Check
tor cause
(Feler
to
specilied
check
sequence)
r?
Page
F-70
"68"
tleshes
Check
ECU t€ffninal ]F voltage
(7
gage F-114
Voltage:
Approx. 12v
(lgnition
switch
ON)
+
lf OK, replace ECU
rpageF-ll2
€.
It nor OK, check wkins belween
ECU and Se f-O agnosis Checker
2
ls there ar leakage o{
intake
air syslem com-
3 ls air cleaner elemeni clean?
17
page
F-62
Aeplace air cleaner element
Are ECU lelm nal
voltages
OK?
(Especialy lK,
2M, 20, 2T and 20)
r.
page
F-112
Check
ior cause
F
Page
F-115
F-117
F-119
5
rs a r bypass soenold
valve
@
OK?
r?
page
F-!09
ai
SOLENOID
INJECTION BOOY
varvE(A\\'
r)
o'
,(4)
:
Beplace soenoid vaive
r7
Page
F-109
F-31