Chevrolet 1980 Light Duty Truck Service Manual page 406

6A-2 ENGINE M E CHA NICAL
a. Check for sufficient fuel to operate engine.
b. Carburetor flooded and/or fuel level in carburetor
bowl not correct.
c. Dirt and water in gas line or carburetor.
d. Sticking choke.
e. Faulty fuel pump.
f. Corroded or loose battery terminal connections and/
or weak battery.
g. Broken or loose ignition wires and/or faulty ignition
switch.
a. Check for air leaks between intake manifold and
head.
b. Check for blown head gasket.
, - . .
c. Check for worn timing gears, chain or sprockets.
d. Check for worn camshaft lobes.
e. Check for overheated engine.
a. Check, inspect and regap spark plugs. Replace as
necessary.
b. Remove moisture from spark plug wires and/or
distributor cap.
c. Check for broken or loose ignition wires. Repair or
replace as necessary.
d. Check condition
compression. Repair as necessary.
e. Check for weak or faulty HEI system coil as outlined
in Section 6D of this manual.
f. Inspect condition of distributor cap and rotor.
Replace if damaged or cracked.
g. Check carburetor for internal obstructions, incorrect
idle speed, faulty altitude compensator, sticking choke or
enrichment system and adjust, repair or replace as
necessary.
h. Inspect carburetor fuel filter for presence of water
and/or impurities and correct as necessary.
i. Check carburetor mounting gasket for air leaks.
DIAGNOSIS
ENGINE FAILS TO START
ENGINE LOPES WHILE IDLING
, . , „
ENGINE MISSES WHILE IDLING
of cylinders for uneven
h. Excessive moisture on plugs, caps or ignition system.
i. Damaged distributor rotor or cracked distributor
cap.
j. Fouled spark plugs and/or improper spark plug gap.
k. Weak or faulty coil.
1. Faulty solenoid or starting motor,
m. Park or neutral switch inoperative.
f. Check for plugged crankcase vent valve,
g. Check for faulty fuel pump.
h. Check for leaky EGR valve.
Repair as necessary.
j. Check distributor spark advance mechanism for
proper operation. Repair or replace as necessary.
k. Inspect valve train components. Adjust, repair and/
or replace as necessary.
1. Check engine for low compression. Repair as
necessary.
m. Check operation of exhaust gas recirculation valve.
Repair or replace as necessary.
n. Check ignition timing, and condition of ignition
system as outlined in Section 6D of this manual. Correct
as necessary.
o. Check for vacuum leaks. Correct as necessary.
p. Check operation of EFE valve as outlined in Section
6E of this manual. Repair or replace as necessary.
LIG H T T R U C K S E R V IC E M AN UAL