Chevrolet Corvette 1963 Repair & Tune-Up Manual page 325

Condition
Engine cranks, but does not
start
Engine stalls
Engine hesitates on
acceleration
Engine feels sluggish or flat
on acceleration
Carburetor floods
TROUBLESHOOTING
Possible Cause
1. Improper starting procedure
2. No fuel in tank
3. Clogged fuel line or filter
4. Defective fuel pump
5. Choke valve not closing properly
6. Engine flooded
7. Choke valve not unloading
8. Throttle linkage not making full travel
9. Stuck needle or float
10. Leaking float needle or seat
11. Improper float adjustment
1. Improperly adjusted idle speed or mixture
Engine hot
2. Improperly adjusted dashpot
3. Defective or improperly adjusted solenoid
4. Incorrect fuel level in fuel bowl
5. Fuel pump pressure too high
6. Leaking float needle seat
7. Secondary throttle valve stuck open
8. Air or fuel leaks
9. Idle air bleeds plugged or missing
10. Idle passages plugged
Engine Cold
11. Incorrectly adjusted choke
12. Improperly adjusted fast idle speed
13. Air leaks
14. Plugged idle or idle air passages
15. Stuck choke valve or binding linkage
16. Stuck secondary throttle valves
17. Engine flooding—high fuel level
18. Leaking or misaligned float
1. Clogged fuel filter
2. Leaking fuel pump diaphragm
3. Low fuel pump pressure
4. Secondary throttle valves stuck, bent or misadjusted
5. Sticking or binding air valve
6. Defective accelerator pump
7. Vacuum leaks
8. Clogged air filter
9. Incorrect choke adjustment (engine cold)
1. Improperly adjusted idle speed or mixture
2. Clogged fuel filter
3. Defective accelerator pump
4. Dirty, plugged or incorrect main metering jets
5. Bent or sticking main metering rods
6. Sticking throttle valves
7. Stuck heat riser
8. Binding or stuck air valve
9. Dirty, plugged or incorrect secondary jets
10. Bent or sticking secondary metering rods.
11. Throttle body or manifold heat passages plugged
12. Improperly adjusted choke or choke vacuum break.
1. Defective fuel pump. Pressure too high.
2. Stuck choke valve
3. Dirty, worn or damaged float or needle valve/seat
4. Incorrect float/fuel level
5. Leaking float bowl
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