LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> GMC >> 1983 >> Forward Control 4.8 T, Standard >> Repair and Diagnosis >> Engine Performance >> System >> EGR Function Testing >> System Testing >> EGR-TVS Test (Cold)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

EGR-TVS Test (Cold)

  1. Engine coolant must be below 85°F (29°C). Drain coolant to below level of switch. Disconnect vacuum lines and remove switch. Inspect switch to make sure it is in good condition.
  2. Connect a vacuum hose to lower nipple of switch, marked "C" or "CARB". Connect a vacuum gauge to upper nipple, marked "E" or "EGR". Place switch in water at 75°F (24°C) and submerge completely for 2 minutes while agitating water thoroughly. Apply 12 in. Hg to hose on lower nipple of switch. Under this condition, switch should be closed.
    NOTE: Leakage of up to 2 in. Hg in 2 minutes is allowable and does not mean a defective switch.
  3. If operation is satisfactory, reinstall switch. If switch is defective, replace with a new part. Replace coolant and check level.
scientia non olet · About LEMON Manuals