Rough Idle/Engine Stalls At Idle - Before Warm-Up - Mazda 121 Workshop Manual

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 - 1 1 7
F - 1 1 9
5
rs a r bypass soenold valve @ OK?
r? page F-!09
a i
SOLENOID
INJECTION BOOY
varvE(A\\'
r )
o'
,(4)
:
Beplace soenoid vaive
r7 Page F-109
F-31