Choke Pull-off: Testing and Inspection

Fig. 31 Troubleshooting Flow Chart. Testing Cranking Leak Solenoid Valve:

Cold Engine
Engine coolant temperature should be below 59°F when performing this test.
1. Disconnect No. 26 vacuum hose from choke opener and connect vacuum pump.
2. Check vacuum with ignition switch turned to START position.
3. If there is vacuum, refer to Fig. 31.
4. Start engine and disconnect No. 18 vacuum hose from choke opener, then connect a vacuum pump. It should not hold vacuum.
5. If vacuum is held, check No. 18 vacuum hose for proper connection, cracks, blockage, or disconnected hose and, if hose is satisfactory, replace thermovalve and repeat test.

Hot Engine
1. Start engine and warm to normal operating temperature.
2. Disconnect No. 18 vacuum hose from choke opener and connect a vacuum pump. It should hold vacuum.
3. If vacuum is not held, check No. 18 vacuum hose for proper connection, cracks, blockage or disconnected hose and, if hose is satisfactory, replace thermovalve and repeat test.
CHOKE OPENER DIAPHRAGM
1. Disconnect No. 18 vacuum hose from vacuum hose manifold.
2. Disconnect No. 26 vacuum hose from vacuum hose manifold and connect a vacuum pump, then apply vacuum.
3. Vacuum should stabilize at 4-8 inches Hg and it should pull the opener rod. If not, check linkage for signs of mechanical binding and replace left carburetor.
4. Cap end of No. 18 vacuum hose and apply vacuum. It should pull opener rod. If not, replace left carburetor.