Hesitates/Stumbles On Acceleration - Mazda 121 Workshop Manual

TROUBLESHOOTING GUIDE
F
1 7 HESITATESFTUIIBLES ON ACCELERATION
DESCND.
TION
.Flat spot occurs lug ater accelerator depressed or mrld jerling occurs during ac.dera on
ITROUBLESHOOTT
G Ht]{TSl
O Air/Fuel mxlure oecom€s rean $nen dep.e€srng accelerator
.Fuel injecllon control malfunction (Corection for accelerating condition)
.Fuel line pressure d€creases
.Spark advance conlfol malfunclion
INSPECTION ACTION
1
ls "00" display€d on SellDiagnosis Checker
wilh ignilion siwilch ON?
I.ltuncllon Code l{o, dhplay€d
Check lor cause (Refer 1o soec'lied
check sequerce)
o page F-70
"88" fl.3hes
Check ECU terminal 1F voliage F page F-114
Vollag€: Approx, 12V
(lgnitlon sw[ch ON]
.> lf OK, rcplace ECU
ri pege F-112
.+ lf not OK, check wiing between
ECIJ and Self-Diagnosis Checker
2
ls there air leakage at iniake air sygem com-
3 ls arr cleaner elsment cl€an?
tr- p.ge F-62
Go to nen siep
Replace air cleaner elemenl
4
Arc ECU t€rminal 1K, 2M, 20 and 20 voltages
OK?
.? p.ge F-l12
Go lo nexl step
N o
Ch€ck ior cause
c7 psge F-1r5
F-117
F-lt9
5 ls lhrotlle linl€ge coreclly inslalled and does
thrcttle valve open frcel',
Cl€an or replace as required any
binding or damaged linkage and ad-
lust cabl€ dell€ction al inieclion body e pag€ F-86
6
ls iuel line pressure correct at idle?
.? p.ge F-94
Fuel line preasure
235-275 kPa (2.4-2.8 tg/cm', 3'F/1() psD
Does ltrel llne pressure decrease
when acceleruting qulcklf
.+ li decreases, check luel line and
liltef lor clogging
4 lf no decrease, go to next slep
Check tuel line pressure whle pinch-
+ lf luel line pressufe quickly iG
creases, check pres$ire regulator
+
11luel line pressure gradually in'
creases, check lor clogging be
tlve€n iuel pump and pressurc
r€gulatot
ll not clogged, check tuel pump
maximurn pressure 17 page F-91
F-43