V 2500 P/U 4WD V8-379 6.2L DSL (1990)
Vacuum Regulator Valve/Throttle Position Switch: Adjustments
Installing vacuum regulator valve gauge bar
1. Loosen vacuum regulator valve, then attach vacuum gauge to the top vacuum nipple.
2. Attach vacuum source to bottom vacuum nipple, then apply 18.5 - 21.5 inches Hg vacuum to nipple.
3. insert a 0.646 inch vacuum regulator gage bar between gauge boss on pump and stop screw.
4. Rotate and hold throttle shaft against gauge bar, then slowly rotate regulator body clockwise until vacuum gauge reads 10.9 - 12.1 inches Hg.
Hold body in this position, then tighten mounting screws to specifications.
5. Allow throttle shaft to return to idle position, then repeat step 4. Readjust valve if necessary.
Throttle position switch adjustment
6. Attach ohmmeter across terminals as shown.
7. Insert switch gauge tool J-29873, between wide open stop pin and wide open stop screw.
8. Rotate throttle lever against gauge tool. There should be no continuity reading.
9. Release throttle lever and remove gauge tool.
10. Rotate throttle lever to wide open throttle position, (so the stop screw and stop pin touch). A reading of 1-ohms must be present before the throttle
reaches wide open throttle position. If reading is not as specified, repeat procedure.