Hard Start
HARD START - COLD
DEFINITION
Engine cranks OK, but does not start for a long time. Does eventually run, or may start but immediately dies and must be re-started. If engine starts but immediately dies (as soon as key is released from start position) check ignition switch, and ignition system for correct "run" signal.
Make sure driver is using correct starting procedure (see owner's manual).
Perform careful visual inspection, check:
- Vacuum hoses for splits, kinks, and proper connections, as shown on vehicle emission control label vacuum diagram.
- Air leaks at carburetor base and intake manifold gaskets.
- Ignition wires for cracks, burned spots or burned ends, hardening, correct firing order, and proper resistance (no more than 30K Ohms per wire).
- Wiring harness for bare spots, pinches, cuts or corroded connections.
Check the choke valve, throttle and fast idle cam for sticking. Replace any malfunctioning parts. If sticking is due to foreign material, greasy dirt or such, clean with suitable non-oil based solvent.
Check choke and vacuum break operation and adjustment. Choke should be closed when cold.
Check EGR system and valve. EGR valve should be closed when the engine is being started or when idling.
Check carburetor float level with external float gauge. Adjust to specification if required.
Check fuel pump pressure and volume.
Check fuel filter, Replace if restricted or plugged.
Check ignition system. Look for:
- Arcing at ignition coil, distributor cap, or plug wires.
- High secondary resistance (test coil and plug wires, should be no more than 30K Ohms in any wire).
- Worn distributor shaft.
- Bare or shorted wires to coil, module or igniter.
- Improper pick-up coil resistance or poor connections.
- Loose ignition coil ground.
- Moisture or carbon tracking inside distributor cap.
Check spark plugs for wetting, wear, improper gap, burned electrodes or heavy deposits. Repair or replace as necessary.
Check ignition timing per Vehicle Emission Control Information label.
HARD START - HOT
DEFINITION
Engine cranks OK, but does not start for a long time. Does eventually run, or may start but immediately dies and must be re-started. If engine starts but immediately dies (as soon as key is released from start position) check ignition switch, and ignition system for correct "run" signal.
Make sure driver is using correct starting procedure (see owner's manual).
Perform careful visual inspection, check:
- Vacuum hoses for splits, kinks, and proper connections, as shown on vehicle emission control label vacuum diagram.
- Air leaks at carburetor base and intake manifold gaskets.
- Ignition wires for cracks, burned spots or burned ends, hardening, correct firing order, and proper resistance (no more than 30K Ohms per wire).
- Wiring harness for bare spots, pinches, cuts or corroded connections.
Check the choke valve, throttle and fast idle cam for sticking. Replace any malfunctioning parts. If sticking is due to foreign material, greasy dirt or such, clean with suitable non-oil based solvent.
Check choke and vacuum break operation and adjustment. Choke should be open when hot.
Check EGR system and valve. EGR valve should be closed when the engine is being started or when idling.
Check carburetor float level with external float gauge. Adjust to specification if required.
Check for carburetor flooding.
Check fuel pump pressure and volume.
Check fuel filter, Replace if restricted or plugged.
Check EFE heater, heater should be "off" when engine is hot.
Check for obvious overheating problems.
- Low coolant level.
- Loose belts
- Restricted water flow through radiator.
- Insufficient air flow to radiator.
Check ignition system. Look for:
- Arcing at ignition coil, distributor cap, or plug wires.
- High secondary resistance (test coil and plug wires, should be no more than 30K Ohms in any wire).
- Worn distributor shaft.
- Bare or shorted wires to coil, module or igniter.
- Improper pick-up coil resistance or poor connections.
- Loose ignition coil ground.
- Moisture or carbon tracking inside distributor cap.
Check spark plugs for wetting, wear, improper gap, burned electrodes or heavy deposits. Repair or replace as necessary.
Check ignition timing per Vehicle Emission Control Information label.