1994 GMC Jimmy Owner's Manual - Page 250

Air Cleaner To remove the round air cleaner filter the 4.3L (VIN 2) engine, turnthe for wing nuts to the left. Remove the cover and change the filter. should be Care taken during reassembly to ensure that the is on straight and the cover wingnuts are properly tightened. To remove the square air cleaner filter the 4.3L (VIN W) high for performance engine, loosen both wingnuts (one on the duct and on the one cover). Lift the air cleaner assembly from the vehicle. Open both clamps and lift up off cover to change the filter. While reassembling the air cleaner assembly, ensure that the air cleaner cover tabs are fully inserted into the slots in the air cleaner housing, two wingscrewsare secured, and thePCV air tube is the properly seated in the left hand valve cover. Refer to the Maintenance Scheduleto determine when to replace the air filter. See "Scheduled Maintenance Services" in the Index. 6-14