ELECTRONIC FUEL INJECTION FUEL LINE REPAIR

1985 S/T AND M VANS WITH THE 2.5L ELECTRONIC FUEL INJECTION (EFI), REQUIRE A DIFFERENT TYPE FUEL SYSTEM THAN THOSE WITH CARBURETORS. WHENEVER THE IGNITION SWITCH IS ENERGIZED OR THE ENGINE IS OPERATING, THE FUEL SYSTEM IS UNDER PRESSURE TO THE EFI. THE FOLLOWING INFORMATION IS BEING PROVIDED TO HELP UNDERSTAND SOME NEW FEATURES OF THE 1985 EFI FUEL SYSTEM. 1. THE ENGINE COMPARTMENT CONTAINS COUPLED HOSE/PIPE ASSEMBLIES. 2. SPECIAL HOSE MATERIAL IS USED WHICH IS RESISTANT TO POOR QUALITY FUEL. 3. STAINLESS STEEL SCREW BAND HOSE CLAMPS ARE USED ON HOSE/PIPE CONNECTIONS WHICH DO NOT HAVE COUPLER FITTINGS. 4. THE FUEL RETURN LINE IS 5/16" DIAMETER AND THE FUEL VAPOR LINE IS 1/4" DIAMETER. THE FOLLOWING GUIDE LINES MUST BE USED WHEN SERVICING THE EFI SYSTEM: 1. COUPLED HOSE ASSEMBLIES ARE NOT TO BE REPAIRED. IF A HOSE IS DAMAGED, IT MUST BE REPLACED AS AN ASSEMBLY. 2. UNCOUPLED FUEL LINES (3/8" FUEL FEED - 5/16" RETURN LINE) THAT MUST BE REPLACED HAVE TO BE MADE OF A FLUROELASTOMER MATERIAL INSTEAD OF A NEOPRENE HOSE. 3. IF A CLAMPED LINE IS OPENED FOR SERVICE, IT MUST BE REASSEMBLED WITH THE SAME TYPE AND NUMBER OF CLAMPS AND TORQUED TO THE PROPER SPECIFICATIONS. FUEL LINE REPAIR REPLACEMENT 1. IF REPLACEMENT OF A FUEL FEED, FUEL RETURN OR EMISSION PIPE REQUIRED USE WELDED STEEL TUBING MEETING GM SPECIFICATION 124-M OR ITS EQUIVALENT. 2. DO NOT USE COPPER OR ALUMINUM TUBING TO REPLACE STEEL TUBING. THOSE MATERIALS DO NOT HAVE SATISFACTORY DURABILITY TO WITHSTAND NORMAL VEHICLE VIBRATIONS. 3. WHEN RUBBER HOSE IS USED TO REPLACE PIPE, USE ONLY REINFORCED FUEL-RESISTANT HOSE WHICH IS IDENTIFIED WITH THE WORD "FLUROELASTOMER" ON THE HOSE. HOSE INSIDE DIAMETER MUST MATCH PIPE OUTSIDE DIAMETER. 4. DO NOT USE RUBBER HOSE WITHIN 4" (100 MM) OF ANY PART OF THE EXHAUST SYSTEM OR WITHIN 10" (254 MM) OF THE CATALYTIC CONVERTER. 5. IN REPAIRABLE AREAS, CUT A PIECE OF FUEL HOSE 4" (100 MM) LONGER THAN PORTION OF THE LINE REMOVED. IF MORE THAN A 6 INCH (152 MM) LENGTH OF PIPE IS REMOVED, USE A COMBINATION OF STEEL PIPE AND HOSE SO THAT HOSE LENGTHS WILL NOT BE MORE THAN 10 INCHES (254 MM). FOLLOW THE SAME ROUTING AS THE ORIGINAL PIPE. 6. CUT ENDS OF PIPE REMAINING ON CAR SQUARE WITH A TUBE CUTTER. USING THE FIRST STEP OF A DOUBLE FLARING TOOL, FORM A BEAD ON THE END OF BOTH PIPE SECTIONS. IF PIPE IS TOO CORRODED TO WITHSTAND BEAD OPERATION WITHOUT DAMAGE, THE PIPE SHOULD BE REPLACED. IF A NEW SECTION OF PIPE IS USED, FORM A BEAD ON BOTH ENDS OF IT ALSO. 7. USE SCREW TYPE HOSE CLAMP, PART NUMBER 2494772, OR EQUIVALENT. SLIDE CLAMPS ONTO PIPE AND PUSH HOSE 2" (51 MM) ONTO EACH PORTION OF FUEL PIPE. TIGHTEN CLAMPS ON EACH SIDE OF REPAIR. 8. PIPES MUST BE PROPERLY SECURED TO THE FRAME TO PREVENT CHAFING.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.