Fuel System - Cold Stall/Cold Performance/Code 44

87buick11

Bulletin 876E23

Date Dec. '87

Ref. No. 87-212-6E

Corp. Ref. No. 786504R

SUBJECT: COLD STALL, COLD PERFORMANCE AND CODE 44


MODELS AFFECTED: 1987 CENTURYS WITH 2.5L L-4 ENGINES (VIN CODE R) 1987 SOMERSETS/SKYLARKS WITH 2.5L L-4 ENGINES (VIN CODE U)
Some 1987 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 a lean exhaust condition.

Code 44 scan diagnosis in your service manual section 6E2 may correct the condition. If it does not, the following procedure may be used:

Check the fuel pressure using a 0-103 kPa (0-15 PSI) gage (J29658). If the fuel pressure is not within the specified 62-90 kPa (9-13 PSI) range, repair the fuel system as necessary. If the fuel pressure is within specification, restrict the fuel return line which increases the fuel pressure and causes more fuel to be discharged from the injector. At the same time, watch the integrator reading on your scanner. It should decrease. If the return line is restricted long enough both the integrator and block learn should stabilize closer together. This indicates a restricted fuel injector and it should be replaced.

NOTE: The block learn may read 128 with the car stopped and idling. It will be necessary to road test the vehicle to have the block learn number follow the integrator.