Engine Stalls/Quits/Runs Rough/Misses/Buck/Jerk/Hesitation/Stumble - Mazda B-Series 1997 Workshop Manual

TROUBLESHOOTlNG GUIDE
FT
1
ENGINE STALLSIQUITS
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ACCELERATIONICRUISE
ENGINE RUNS ROUGH ACCELERATIONICRUISE
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ACCELERATIONlCRUISE/DECELERATlON
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ACCELERATION
1
Engine stops unexpectedly at beginning of acceleration or during acceleration
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Engine stops unexpectedly while cruising
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Engine speed fluctuates during acceleration or cruising
DESCRIPTlON
Engine misses during acceleration or cruising
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Vehicle bucksljerks during acceleration, cruising, or deceleration
'
:
Momentary pause at beginning of acceleration or during acceleration
- - P A
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INSPECTION ACTION
=
page FT-71
- -
US
page FT-77
Go to next steD
Disconnect vacuum hose from EGR valve and plug Yes
Check EGR vent on vacuum hose to EGR valve for
It.
~
~
obstruction or leak
Is drlve symptom el1minated7
If OK, replace EGR vacuunn regulator solenold
1
If not OK, repair or replace vacuum hose
a -
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- p p
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No Go to next step
p p , - - P -
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-
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p -
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Does EGR valve seat properly' Yes Go to next step
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P -
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valve and EGR v,acuum regulator
=
page FT-158,159
Start engine. Disconnect crankcase ventilation hose
from the throttle body. Place a stiff piece of paper
over the hose end.
Does vacuum hold the paper?
4
Perform Fuel Line Pressure Inspection.
=
page FT-150
Is fuel line pressure correct?
Remove PCV valve and shake it.
Does PCV valve rattle?
Fuel line pressure:
240-280 kPa (2.5-2.8 kgflcm2, 35-40 psi)
Visually look for fuel leakage at injector O-ring,
pressure regulator, and fuel line. Service as
necessary.
Perform Fuel Pressure Hold Inspection.
=
page FT-150
Does fuel line pressure hold?
Yes
No
Yes
- -
No
Yes
Yes
Install PCV valve
Go to next step
Replace PCV valve
Go to next step
Check evaporative emission system as follows:
Disconnect evaporative hose .and place a stiff piece
of paper over hose
Does vacuum hold paper?
If yes, check evaporative emission system
page FT-160
If no, check for vacuum leak in PCV system, oil
cap, PCV valve, rocker cover for bolt torquelgasket
leak
- - P p - p p - p
Go to next step
- - P p ~ - - - - - - - p p p p
Zero or low:
Check pressure regulator diaphragm
=
page FT-154
Check fuel pump circuit
US
page FT-151
High:
Check pressure regulator for high pressure cause
@
page FT-154
Check for clogged fuel return line
Go to next step
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Check pressure regulator diaphragm condition
E *
page FT-154
If condition is OK, check injector
ah.
page FT-155
If condition is not OK, replace pressure regulator