Deceleration Fuel Shut-Off Check
- Engine oil temperature must be at minimum of 120°F (50°C). Reconnect wiring to temperature sensor. Start engine and run it at 2000 RPM briefly. Release throttle.
- Differential pressure regulator current reading should briefly be negative (-30 to -60 mA) and return to positive when engine reaches approximately 1300 RPM. If not, check for open idle switch signal at ECU connector terminals No. 2 and 13. If switch is good, replace ECU.