1987 MAZDA 626 Exhaust

TROUBLESHOOTING GUIDE 4D
TROUBLESHOOTING GUIDE
Condition Condition Cause Remedy
Hard starting Fuel filter
Clogged Replace
Water or air in filter Repair
Fuel injection pump Faulty fuel cut solenoid Replace Incorrect injection timing Adjust
Air in pump Bleed
Faulty pump Replace
Fuel injection nozzle Seized needle valve Replace
Fuel dripping from nozzle Replace Incorrect valve opening pressure Adjust
Faulty glow plug Replace
Faulty cold start device Adjust or replace
Faulty supercharging system Refer to page 4D—10
Rough idle Fuel filter (Refer to "Hard starting") Fuel injection pump (Refer to "Hard starting")
Fuel injection nozzle
Seized needle valve Replace
Incorrect valve opening pressure Adjust
Improper mounting to nozzle holder Repair
Leakage of nozzle holder copper washer Replace
Fuel injection pipe Cranks Replace
Leaking from joint Repair
Improper idle speed adjustment Adjust
Engine knocking Incorrect injection timing Adjust
Low quality fuel Replace
Incorrect injection nozzle opening pressure Ajust
Seized injection nozzle needle valve Replace
Fuel dripping from injection nozzle Replace
Faulty supercharging system Refer to page 4D—10
High fuel Fuel injection pump consumption Incorrect injection timing Adjust consumption High idle speed Adjust, Inspect the dashpot
Fuel injection nozzle Incorrect valve opening pressure Repair
Fuel dripping from nozzle Replace
Leakage of nozzle holder copper washer Replace
Fuel leaking from connection Repair
Clogged fuel filter Replace
Clogged air cleaner Replace
Poor acceleration Fuel injection nozzle (Refer to "Hard starting")
Fuel injection pump (Refer to "Hard starting")
Fuel injection pipe (Refer to "Rough idle") Fuel filter (Refer to "Hard starting") Clogged air cleaner Clean or replace
Faulty supercharging system Refer to page 4D—10
Excessive exhaust Clogged air cleaner Clean or replace
smoke Improper injection timig Adjust
Faulty nozzle or nozzle holder Adjust or replace
Faulty supercharging system Refer to page 4D—10
76G04D-003
4D-3

4D ON-VEHICLE MAINTENANCE
IDLE SPEED
1. Warm up the engine to normal operating tem-
perature.
2. Be sure the A/C switch is OFF.
3. Connect a tachometer and check the engine
speed.
Idle speed: 720 :
20
rpm
76G04D-012
4. If necessary, adjust the idle by turning the idle ad-
justing screw.
76G04D-013
Fast Idle Speed (A/C equipped model)
1. Turn ON the A/C switch and blower motor switch.
2. Check the engine speed.
Fast idle speed: 725 ± 25 rpm
3. If necessary, turn the adjusting screw on the idle-
up actuator, and adjust the fast idle speed.
76G04D-014
EXHAUST SMOKE
Increase and decrease the engine speed several
times and check that there is no black smoke.
If
there
is, refer to the Troubleshooting Guide.
76G04D-015
4D—6

INTAKE AIR SYSTEM 4D
INTAKE MANIFOLD
Removal and Installation
1. Remove in the sequence shown in the figure.
2. Install in the reverse order of removal.
3. Check for air/exhaust leakage.
76G04D-020
3. Vacuum hose (RF-CX)
4. Water thermo switch connector
5. Intake manifold
Inspection
1. Check the intake manifold for cracks and damage.
2. Inspect the flatness of the mounting surface using
a straight edge and a feeler gauge. Replace if
necessary.
Distortion: 0.05 mm (0.002 in) max.
19—26 N m (1.9—2.6 m-kg, 14—21 ft-lb)
8—11 N-m (80—110 cm-kg, 69—95 in-lb)
8—11 N-m (B0—110 cm-kg, 69—95 In-lb)
8—11 Nm (80—110 cm-kg, 69—95 In-lb)
19—26 N-m (1.9—2.6 m-kg, 14—19 ft-lb)
34—49 N-m (3.5—5.0 m-kg, 25—36 ft-lb)
8—11 N-m (80—110 cm-kg, 69—95 in-lb)
19—26 N-m (1.9—2.6 m-kg, 14—19 ft-lb) 22—26 N-m (2.2—2.7 m-kg, 16—20 ft-lb)
22—26 N m (2.2—2.7 m-kg, 16—20 ft-lb)
8—11 N-m (80—110 cm-kg, 69—95 in-lb)
1. Comprex supercharger
(Refer to page 4D—13.: RF-CX)
2. Exhaust manifold
(Refer to page 4D—19.: RF-CX)
76G04D-021
4D-9

4D SUPERCHARGING SYSTEM (RF-CX)
SUPERCHARGING SYSTEM (RF-CX)
TROUBLESHOOTING GUIDE

Engine
hard
starting

Poor

acceleration

Excessive

blue
smoke

Excessive

black
smoke

Excessive

compressed
air
temperature
(Buzzser
sounds)

Excessive

noise
Possible Cause Remedy (reference page)
*
*
Comprex supercharger Rotor stuck Casing damaged Rotor bearing damaged
Replace (4D—14)
* * * Drive system
of
Comprex supercharger Drive belt loose
or
worn Repair
or

replace
(4D-12) * Idler pulley damaged
Repair
or

replace
(4D-12) * Pulley bolt loose
or
worn
Repair
or

replace
(4D-12)
* Wastegate
Valve
not
open Clean
or
repace (4D-12) ik * Valve
not
closed
Clean
or
repace (4D-12)
* * Starting valve
Valve
not
open Repair
or
replace (4D-15)
* * Valve
not
closed
Repair
or
replace (4D-15) * Bypass valve
not
open
Repair
or
replace (4D-15)
* * Bypass valve
not
closed
Repair
or
replace (4D-15)
* Intercooler dirty Clean
or
replace (4D-16)
* * * * Intake
air
system Fresh
air
side clogged (Air cleaner
ele-
ment,
etc.)

Repair
or
replace * Compressed
air
side clogged (Intercool-
er,
etc.)
Repair
or
replace
* Fresh
air
side leaks
Repair
or
replace
* * * Compressed
air
side leaks
Repair
or
replace
* Exhaust system
Exhaust
gas
breaked Repair
* * * * * Exhaust pipe clogged
Repair
* Silencer damaged
(in
fender,
in air
clean-er,
in air
funnel, Comprex insulator) Repair
or
replace
* Bolt
and nut
loosend Repair
76G04D-022
4D—10

4D SUPERCHARGING SYSTEM (RF-CX)
ON-VEHICLE INSPECTION
Boost Pressure
1. Connect a pressure gauge to the hose from the
intake manifold.
2. (On chassis dynomometer, full load)
(1) Set the vehicle on a chassis dynomometer.
(2) Run the vehicle in gear at 3,000 rpm with the
acceleration pedal fully depressed.
(3) Measure the boost pressure.
Boost pressure:
82 kPa (0.87 kg/cm2, 8.1 psi)
Note
The above inspection should be done on a
chassis dynomometer. If a dynomometer is
not available follow the below procedure.
3. (Off chassis dynomometer, no load)
(1) Shift the transaxle out off gear.
(2) Run the engine in neutral at 3,000 rpm of the
engine no load.
Measure the boost pressure.
Boost pressure:
5 kPa (0.05 kg/cm2, 0.7 psi)
Note
The boost pressure is varied by engine speed
and engine load.
(3) Remove the starting valve bypass hose.
(4) Check that the bypass valve is closed at 3,000
rpm.
4.
If
the pressure is below specification, check the fol-
lowing. Replace the Comprex supercharger if
necessary.
(1) Intake air and exhaust passages leakage
(2) Intake air and exhaust passages clogged
(3) Wastegate (Refer to 4D—12.)
(4) Starting valve (Refer to 4D—15.)
(5) Fuel system (Injection nozzle... refer to page
4D—31, injection pump...refer to page 4D—24,
etc.)
5. If the pressure exceeds specification, check the
wastegate operation. (Refer to page 4D—12.)
4D—11

SUPERCHARGING SYSTEM (RF-CX) 4D
COMPREX SUPERCHARGER
Removal and Installation
1. Remove in the sequence shown in the figure.
2. Install in the reverse order of removal.
3. Check for air/exhaust leakage.
8—11 N m ''"'^'gs , (80—110 cm-kg, 69—95 In-lb)
8—11 N-m (80—110 cm-kg, 69—95 In-lb)
IsSJ 19-26 N-m (1.9—2.6 m-kg, 14—19 ft-lb)
34—49 N m (3.5—5.0 m-kg, 25—36 ft-lb)
22—26 N-m (2.2—2.7 m-kg, 16—20 ft-lb)
76G04D-029
1. Air hose
2. Air funnel assembly
3. Exhaust pipe
4. Supercharger insulator
5. Exhaust manihold stay
6. Drive belt
7. Exhaust joint pipe
8. Idle pulley
9. Comprex supercharger
Caution
a) Be careful not to bend the rod or bracket
of the wastegate.
b) Cover the intake and exhaust ports to pre-
vent dirt or other material from entering.
76G04D-030
4D—13

4D SUPERCHARGING SYSTEM (RF-CX)
Inspection
Air casing, exhaust casing, rotor housing
Check the air casing, exhaust casing, and rotor hous-
ing for cracks or damage. Replace the Comprex su-
percharger if necessary.
76G04D-031
Rotor and rotor bearing
Check that the rotor turns smoothly. Replace the Com-
prex supercharger if necessary.
76G04D-032
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Air funnel
Check the air funnel and insulator for cracks or
damaged. Replace if necessary.
76G04D-033
4D—14

4D EXHAUST SYSTEM
EXHAUST SYSTEM
STRUCTURAL VIEW
1. Exhaust manifold 4. Pre-silencer
2. Comprex supercharger (RF-CX) 5. Main silencer
3. Air funnel assembly
4D-18