Full Load Regulation System
PURPOSE: To make sure that under full load with engine coolant temperature above 18°C, the OCR value is fixed at 35% (31° to 32° on dwell meter).
1. Start the engine.
Fig. 25 Full load vacuum switch:
2. Disconnect vacuum hose (green) from the full load vacuum switch (M176), Fig. 25, and seal off the open end of the hose. The reading on the OCR tester must be at 35% (31° to 32° on dwell meter).
Fig. 26 Full load vacuum switch test:
3. If the value is different check as follows, Fig. 26:
a. Stop the engine.
b. Connect an ohmmeter between pin 7 of the ECU connector and ground.
c. Connect vacuum pump to full load vacuum test switch.
d. Check that the resistance goes from less than 1 ohm to infinity when the vacuum applied to the full load switch reaches 85 mm Hg (3.35 in Hg).
e. If this is not so check the electrical circuit's continuity. If it is, replace the full load vacuum switch (M176), Fig. 25.