LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> GMC >> 1992 >> Forward Control 6.2 J, Standard >> Repair and Diagnosis >> Engine Mechanical >> Auxiliary Emission Control Systems >> EGR Function Testing >> EGR Function Testing >> Diesel EGR
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diesel EGR

  1. Turn engine off. Disconnect vacuum hose to EGR valve. Connect a hand-held vacuum pump to EGR valve and apply 10 in. Hg. EGR pintle should move up and stay up for at least 20 seconds. If not, replace EGR valve.
  2. To check vacuum pump operation, connect vacuum gauge to vacuum inlet (small fitting). DO NOT plug or disconnect outlet fitting. With engine idling, vacuum should be at least 18 in Hg one minute after start. If not, check for belt slippage, vacuum leaks or other obvious defects. If vacuum reading is as specified, replace EGR valve.
scientia non olet · About LEMON Manuals