Engine - Cold Stall/Cold Performance and Code 44
87chevy23Number: 87-251-6E
Section: 6E
Date: DEC., 1987
Subject: COLD STALL, COLD
PERFORMANCE AND CODE 44
Model and Year: 1987 CELEBRITY MODELS
EQUIPPED WITH 2.5L ENGINES
TO: ALL CHEVROLET DEALERS
Some 1987 Celebrity 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 a fuel pressure check. If fuel pressure is not within specification, repair the fuel system as necessary. If fuel pressure is within specifications, restrict the fuel return line and watch the integration reading. The 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 the fuel line is restricted long enough integration and block learn will stabilize. This indicates a restricted fuel injector. Replace the injector using the applicable labor operation number and time.
NOTICE: The block learn reading may be at 128 while diagnosing the vehicles in a service stall. It will be necessary to road test the vehicle to get the block learn numbers to follow the integrator.