Mazda B-Series 1997 Workshop Manual page 387

FT
TROUBLESHOOTING GUIDE
I
STEP INSPECTION
I ACTION
1
4
:
D~sconnect the Inertla fuel shutoff switch connector. Yes Go to next step
I
Crank engine for 5 seconds.
1
Does pressure drop more than 34 kPa
(0.35 kgf/cm2, 5 psi) by the end of 5 second
crank cycle?
- -
- -
- - -
-
- -
- -
;-iDoes engine stan and run smoothly at part Idle?
Is voltage at throttle position sensor connector
I
No
)
Check resistance of injector(s) at PCM connector
1
If res~stance 1 s OK, check as follows
Injector drive s~gnal
Injector flow rate
PGM
If resistance 1 s not OK, check for open in Injector
c~rcult
- - - - -
- -
- -
Check Idle alr control solenold and wlrlng harness
m
page FT-147
Check throttle body for damage
a*
page FT-146
CheckPCM
a*
page FT-164
termins VREF between 4.0 volts and 6.0 volts with
the ignition switch ON?
Repair open in VREF circuit
N o
a*
oaae FT-144
1
high-tension lead'while cranking engine?
- -
7
8
Disconnect vacuum hose from EGR valve and
plug it.
Is drive symptom eliminated?
I -
- .
10 Does EGR valve seat properly (fully closed)?
-
i
-
Key on engine off.
Measure voltage between Pin 13 (module
programming signal) at data link connector and
battery negative post.
Is voltage greater than 9.0 volts?
Is a strong blue spark visible at each disconnected
-
No
Check camshaft pos~t~on sensor slgnal at PCM
-
page FT-168,174,180
If OK, check as follows.
Crankshaft posltlon sensor
r F
H~gh-tenslon leads
=
Section G
Section G
Spark plugs
a *
Section G
-
,
If not OK, check wlrlng harness
--
Yes
Check EGR vent on vacuum hose to EGR valve for
obstruct~on or leak
If OK, replace EGR vacuum regulator solenold
If not OK, repalr or replace vacuum l~ne
-
- -
- -
- - -
-
-
-
No Go to next step
- -
- -
- -
-
--
Yes Go to next step
-
p p
- - -
- - -
- -
No Check as follows:
=
page FT-158,159
EGR valve malfunction
EGR flange gasket leak~ng
EGR valve attach~ng nuts or bolts loose or mlsslng
EGR valve contamlnatlon
EGR
vacuum regulator solenord malfunct~on
Yes
No
.
-
Repair Pin 13 circuit short to power
Go to next step
11
12
13
Y = ( ~ o x t step
MF1462-F2 6BUOFT-015
Is there a restr~ct~on ~n exhaust system? Yes Check exhaust system
a9-
page FT-156
=
page FT-156
No Go to next step
Go to next step
Check for cause
For 2.3L: Section 61
For 3.OL: Section 62
For 4.OL: Section B3
Is englne
compression
correct?
Verlfy test results If OK, return to d~agnost~c index to servlce any add~t~onal symptoms
Yes
No