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

TROUBLESHOOTING GUIDE
F
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ROUGH IDLE/ENGINE STALLS AT IDLE - AFTER WARII.UP
DESCRIP.
TION
.Engine runs normally al idle during wam-up but engine stalls or vibrales excessively afler warm-up
ITROUaLESHOOTTNG
HINTSI
O) rdle speed contror svslem mallunction
@ Air/Fuel mixture loo lean
.Low fuel line pressure
. PCV vatve stuck (open)
@ ArlFuel mi(ure too nch
.Fuel injecl on control mal,unclion
(Corection ior coolanl temperature)
@ Poor ignilion
O Low engine compress on
INSPECT|oiT
ACTION
1 ls 00" displayed on Self-Diagnosis Checker
with ignilion switch ON?
e page F-67
llalluncfion Code ilo. displ.yed
Check lor cause Geler lo so€cilied
ch€ck sequence)
(? page F-m
"8a" tlashes
Check ECU termina lF vollage
c7 page F-114
Volreg€: Approx. r2V
(lgnition switch ON)
+
li OK, replace ECU rz page F-112
+
ll noi OK, check wiring bolween
ECU and SellDiasnosis Checker
2 Are ECU lerminal voltages OK?
(Especially 1K, 2M, 20 and 20)
F page F-112
Check ior caus€ c7 page F-115
F-117
F-r9
3
Disconnect highlension lead at dle; does en-
glne speed d€crease equally al al cylinders?
Go to Slep 10
ls ihere air leakage ol intake arr system com-
5 ls air cleaner element cl€an?
e page F-62
N o R€place alr cleaner element
6
lurn thronle adjusling screw c,
does idle condilion improve?
AIFFLOW SENSOR I
-ffiqf l";;I
Adjust idle speed
.? page F-62
N o
Relurn lhrottle adiusling screw to its
original positlon, and go to next slep
=.\\\
/
F-33