Throttle Valve Switch: Function
- Closed throttle valve switch controls injection quantity for idle, switches off injection during deceleration fuel shutoff and ignition point setting at idle. Open valve switch controls fuel quantity at full throttle.
- Disconnect wiring lead from throttle valve switch. Install ohmmeter between terminals on wiring lead. Reading should show continuity at idle and full throttle position of throttle valve switch.
- To check switching point, open and close throttle valve slowly. When ohmmeter indicates continuity at idle stop position, measure gap between idle stop and idle adjusting screw with feeler gauge. See Fig 1 .
- Gap should be .002-.004" (.05-.10 mm). Proper adjustment of throttle valve switch is important. Excessive gap will cause engine surge when throttled slightly.
- Insufficient gap causes cold engine to stall at full throttle acceleration and warm engine will have no deceleration fuel shutoff. If gap requires adjustment, see THROTTLE VALVE SWITCH ADJUSTMENT under ADJUSTMENTS in this section.
CAUTION:
DO NOT perform following test unless plug is disconnected from ECU.