Pontiac Fiero 1988 Service Manual page 395

6D2-2 CRANKING SYSTEM
t - S H I F T L E V E R
2 - P L U N G E R
3 - H O L D IN C O I L
4 - P U L L IN C O I L
5 - SOLENOSD
6 - S O L E N O I D
SWITCH
C O N T A C T S
7 - T O D I S T R I B U T O R
" B A T " T E R M I N A L
8 -
B U L K H E A D
C O N N E C T O R
9 - BAT.(B+)
1 0 - I G N I T I O N &
S T A R T E R SWITCH
1 1 - B A T T E R Y
1 2 - C R A N K I N G
MOTOR
1 3 - S H I F T C O L L A R
1 4 - PINION
COMPRESSION
SPRING
1 5 - C L U T C H
1 6 - PINION
17- F L Y W H E E L
Fig.
1 Cranking Circuit - 5 M T or PMGR
PROBLEM
HIGH PSYCHSD WHINE DURING CRANKING (BEFORE
ENGINE FIRES) BUT ENGINE CRANKS AND FIRES
OKAY.
HIGH PITCHED "WHINE" A F T E R ENGINE FIRES. AS
K E Y IS BEING R E L E A S E D . ENGINE CRANKS AND
FIRES O K A Y . THIS INTERMITTENT COMPLAINT IS
OFTEN DIAGNOSED AS " S T A R T E R HANG-IN" OR
"SOLENOID WEAK."
A LOUD "WHOOP" A F T E R THE ENGINE FIRES BUT
WHILE THE STARTER IS S T I L L H E L D ENGAGED.
SOUNDS L I K E A SIREN IF T H E ENGINE IS R E V V E D
WHILE STARTER IS ENGAGED.
A "RUMBLE", "GROWL" OR (IN S E V E R E CASES) A
"KNOCK" AS THE STARTER IS COASTING DOWN TO
A STOP A F T E R STARTING THE ENGINE.
CAUSE
DISTANCE TOO GREAT BETWEEN STARTER PINION AND
FLYWHEEL.
DISTANCE TOO SMALL BETWEEN STARTER PINION AND
F L Y W H E E L . FLYWHEEL RUNOUT CONTRIBUTES TO THE
INTERMITTENT NATURE.
MOST PROBABLE CAUSE IS A D E F E C T I V E CLUTCH. A NEW
CLUTCH WILL OFTEN CORRECT THIS PROBLEM.
MOST PROBABLE CAUSE IS A BENT OR UNBALANCED
STARTER ARMATURE. A NEW ARMATURE WILL OFTEN
CORRECT THIS PROBLEM.
520026-6P
Fig. 2 Starter Motor Noise Diagnosis
location will decrease the clearance by
approximately .3mm (.010").
If normal starter shims are not available, they can
be improvised from plain washers or other suitable
material.
Starter Motor:
If the battery, wiring and
switches are in satisfactory condition, and the engine
is known to be functioning properly, remove the motor
and follow the procedures shown in Starter Motor
Disassembly, Test and Reassembly (Unit Repair).
Never operate the cranking motor more than 30
seconds at a time without pausing to allow it to cool
for at least two minutes. Overheating, caused by
excessive cranking, will seriously damage the cranking
motor.