Deceleration Fuel Cut-Off System: Testing
- Disconnect wiring connector from throttle switch. Use ohmmeter to ensure there is good connection between plug on throttle switch and ground when the throttle switch is released. Reconnect wiring to switch.
- Connect Bosch Tester (KDJE 7453) to 2-pole test socket located in front of fuse box. Run engine at 875 RPM. Disconnect wiring connector from vacuum valve.
- Using voltmeter, check that there are 12 volts between connector and ground. Reconnect wiring to vacuum valve and increase engine speed to 2000 RPM. Release accelerator suddenly.
- Use hand to feel if vacuum valve is operating. Sharp reduction in engine RPM also indicates that valve is working. Check that Lambda system assumes a fixed pulse relation (60%) until system cuts out at 1300-1450 RPM.