Pontiac tempest 1968 Service Manual page 342

E N G I N E TUNE-UP 6C-3
• Contact points with an overall gray color and
only slight roughness or pitting need not be
replaced.
• Dirty points should be cleaned with a clean point
file.
Use only a few strokes of a clean, fine-cut
contact file. The file should not be used on other
metals and should not be allowed to become
greasy or dirty. Never use emery cloth or sand­
paper to clean contact points since particles
will embed and cause arcing and rapid burning
of points. Do not attempt to remove all rough­
ness nor dress the point surfaces down smooth.
Merely remove scale or dirt.
• Replace points that are burned or badly pitted.
Where burned or badly pitted points are en­
countered, the ignition system and engine should
be checked to determine the cause of trouble so
it can be eliminated. Unless the condition caus­
ing point burning or pitting is corrected, new
points will provide no better service than the
old. See section 6E for condenser check.
• On 6 cyl. engines, adjust distributor point gap
to .019" (new points) or .016" (used points),
using a flat feeler gauge. Breaker arm rubbing
block must be on high point of lobe during
adjustment.
NOTE: Used contact points should be cleaned be­
fore adjusting with a feeler gauge.
9. Lubricate distributor breaker cam sparingly
with distributor cam lubricant.
10. Install rotor and distributor cap. Press all
wires firmly into cap towers.
SERVICE BATTERY AND BATTERY CABLES
State o f Charge Test
1. Measure the specific gravity of the electrolyte
in each cell. If it is below 1.230 (corrected to 80°F.),
recharge with a slow rate charger, and recheck
battery.
2. Connect a voltmeter across the battery ter­
minals and measure the terminal voltage of the
battery during cranking (remove the coil secondary
lead during this check to prevent engine from firing).
If the terminal voltage is less than 9.0 volts at room
temperature, approx. 80°F.), the battery should be
further checked. See section 12 for battery check­
ing procedure using the "421" Tester.
Inspect for signs of corrosion on battery, cables
and surrounding area, loose or broken carriers,
cracked or bulged cases, dirt and acid, electrolyte
leakage and low electrolyte level. F i l l cells to proper
level with distilled water or water passed through
a demineralizer.
The top of the battery should be clean and the
battery hold-down bolts properly tightened. Particu­
lar care should be taken to see that the top of the
battery is kept clean of acid film and dirt because of
the high voltage between the battery terminals. For
best results when cleaning batteries, wash first with
a dilute ammonia or soda solution to neutralize any
acid present and then flush off with clean water.
Care must be taken to keep vent plugs tight so that
the neutralizing solution does not enter the cell. The
hold-down clamp should be kept tight enough to pre­
vent the battery from shaking around in its holcjr,
but it should not be tightened to the point where the
battery case will be placed under a severe strain.
To insure good contact, the battery cables should
be tight on the battery posts. If the battery posts or
cable terminals are corroded, the cables should be
cleaned separately with a soda solution and a wire
brush. After cleaning and before installing clamps,
apply a thin coating of petrolatum to the posts and
cable clamps to help retard corrosion.
If the battery has remained undercharged, see
Charging Circuit - Preliminary Checks, section 6E.
If the battery has been using too much water, the
voltage regulator setting is too high.
GENERATOR AND REGULATOR
Unsatisfactory results obtained during battery test­
ing may indicate further tests and adjustments to
the generator and regulator as outlined in Engine
Electrical.
FAN BELT
1. Inspect fan belt condition.
2. Check and adjust if necessary for correct ten­
sion of belt, as follows:
a. Using a Burroughs tension gauge check the
fan belt midway between the water pump pulley and
generator pulley.
b. Adjust generator on its mounting bracket to
proper fan belt tension. See section 6A.
CHECK OPERATION OF MANIFOLD HEAT VALVE
Check manifold heat control valve for freedom of
operation. If shaft is sticking, free it up with heat
valve lubricant Pt. No. 1050422 or equivalent.
CHECK INTAKE MANIFOLD BOLTS
To check for a possible leak at the intake mani-