COLD PERFORMANCE POOR, STALL AND CODE 44 (DIAGNOSIS)

COLD STALL, COLD PERFORMANCE AND CODE 44

1987 6000 AND GRAND AM MODELS EQUIPPED WITH 2.5L ENGINES

Some 1987 6000 and Grand Am models equipped with 2.5L engines may experience poor cold performance and code 44, and may not stay running. In order to diagnose this condition, observe the block learn and integrator readings on the scan tool. The readings will be high indicating lean exhaust condition.

Follow code 44 scan diagnosis in your service manual section 6E2.

Perform fuel pressure check. If pressure is not within specification, repair fuel system as necessary. If fuel pressure is within specifications, restrict the fuel return line and watch your integration reading. Reading should come down. By restricting the fuel return line you have raised fuel pressure in the system which causes more fuel to be discharged from the injector. If you restrict the fuel line long enough integration and block learn will stabilize. This indicates a restricted fuel injector. Replace injector using the applicable labor operation number and time.

NOTICE: The block learn reading may be at 128 reading while you are diagnosing in your stall. It will be necessary to road test vehicle to get the block learn numbers to follow the integrator.

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.