Chevrolet Light Duty Truck 1973 Service Manual page 405

a. Carburetor idle speed set too low and/or idle
mixture too rich or too lean.
b. Carburetor needle valve and seat inoperative.
c. Incorrect carburetor float level and/or carburetor
flooding.
d. Dirt or water in gasoline or carburetor.
e. Choke improperly adjusted or sticking.
f. Faulty ignition system.
g- Spark plugs damp or dirty and/or gaps incorrectly
set.
h. Faulty coil or condenser.
i. Distributor points burned, pitted, dirty, or incor­
rectly set.
a. Weak coil or condenser.
b. Incorrect ignition timing.
c. Excessive play in distributor shaft or distributor
cam worn.
d. Insufficient point dwell.
e. Spark plugs dirty or gaps incorrectly set.
f. Carburetor not functioning properly.
g- Improper carburetor float level.
h. Carburetor fuel mixture too rich or too lean.
i. Foreign matter, such as dirt or water, in gas line or
carburetor.
J- Faulty fuel pump.
k. Valve spring weak and/or valves sticking when hot.
a. Improperly seated or broken fuel pump gasket.
b. Improperly seated or broken push rod cover gasket.
c. Improperly seated or broken oil filter gasket.
d. Broken or improperly seated oil pan gasket.
e. Gasket surface of oil pan bent or distorted.
f. Improperly seated or broken timing chain cover
gasket.
ENGINE STALLS
CAUSE
j- Distributor advance inoperative.
k. Exhaust system restricted.
1
.
m. Incorrect valve lifter clearance.
n. Burned, warped, or sticking valves.
0
P- Engine overheating.
q-
r. Leak in exhaust gas recirculation valve.
ENGINE HAS NO POWER
CAUSE
l. Valve timing incorrect.
m. Incorrect valve lifter clearance.
n. Worn camshaft lobes.
0
P- Blown cylinder head gasket.
q-
r. Flow control valve inoperative (Power Steering).
s. Clutch slipping.
t. Brakes dragging.
u. Engine overheating.
V .
w. Sub-standard fuel.
EXTERNAL ENGINE OIL LEAKAGE
CAUSE
g-
h.
j-
k.
Leaks in carburetor mounting gasket or intake
manifold.
Low compression.
.
Loose, corroded, or leaking wiring connections
(bulkhead connector, etc.)
Pistons incorrectly fitted in block.
.
Low compression.
Transmission regulator valve sticking (Hydra-
Matic).
Worn timing chain cover oil seal.
Worn or improperly seated rear main bearing oil
seal.
Loose oil line plugs.
Engine oil pan drain plug improperly seated.
Rear camshaft bearing drain hole plugged.
Loose rocker arm cover, gasket broken, or cover
distorted or bent.
ENGINE 6-69
LIGHT DUTY TRUCK SERVICE MANUAL