GM Service Manual Online
For 1990-2009 cars only

REDUCING CRANKING TIME ON DIESELS

WHEN REPLACING A FUEL FILTER, INJECTION PUMP, OR WHEN THE CAR HAS BEEN RUN OUT OF FUEL ON 1981 AND 1982 MODELS, THE HOUSING PRESSURE COLD ADVANCE (H.P.C.A.) SHOULD BE ACTIVATED MANUALLY IF THE ENGINE TEMPERATURE IS ABOVE 125 DEG. F (52 DEG C). ACTIVATING THE H.P.C.A. SOLENOID, DISCONNECT THE TWO LEAD CONNECTOR AT THE ENGINE TEMPERATURE SWITCH ON P. 6C5-4 OR 6C5-6 OF THE CHASSIS SERVICE MANUAL) AND BRIDGE THE CONNECTOR WITH A JUMPER. AFTER THE ENGINE IS RUNNING, REMOVE THE JUMPER AND RECONNECT THE CONNECTOR TO THE ENGINE TEMPERATURE SWITCH.

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.