Vacuum Regulator Valve/Detent Switch Adjustment (Diesel)
- Loosen vacuum regulator valve so it is free to rotate on pump. Attach a hand-held vacuum pump and apply 20 in. Hg. to bottom port of valve. Attach vacuum gauge to top port of valve.
- Insert 0.646" Gauge Block (J-33043-A) between gauge boss on injection pump and wide open stop screw on throttle lever (switch on position). See Fig 1.NOTE: Always refer to Emission Control Label for correct gauge block size.
- Rotate and hold throttle shaft against gauge block. Slowly rotate vacuum regulator valve body clockwise (facing valve) until vacuum gauge reads 10.9-12.1 in. Hg. Hold valve body at this position and tighten mounting screws.
- Check adjustment by allowing throttle shaft to return to idle stop position. Then rotate throttle shaft back against gauge block. Vacuum gauge reading must be between 10.9-12.1 in. Hg. If vacuum is outside limits, reset valve.
- With vacuum valve set, confirm detent switch point by reading resistance between ignition (Pink/Black wire) and detent terminal (Orange wire). Insert Switch Gauge (J-36142) between wide open stop pin and wide open stop screw on throttle lever. See Fig 1.
- Rotate throttle lever against switch gauge. Continuity should NOT be present. Release throttle lever and remove gauge. Rotate throttle lever to wide open throttle (lever stop screw touching pump stop pin).
- Check switch for continuity. Switch must have 0-1 ohm resistance before throttle reaches wide open position. If switch does not meet specifications, reset assembly by returning to step 1) and repeating entire procedure.