Fuel Pump - Cold Start Stall, Hesitation, Loss of Power

NUMBER:
92-T-117

CORP.REF.NO.:
276103

DATE:
September 1992

SECTION:
6E3



SUBJECT
FUEL PUMP RELATED DRIVEABILITY ISSUES - DIAGNOSTIC INFORMATION


MODELS/YEARS
1987-92 CUTLASS CALAIS, ACHIEVA, CUTLASS CIERA,CUTLASS SUPREME, EIGHTY EIGHT, NINETY EIGHT, TORONADO, BRAVADA AND SILHOUETTE



CONDITION:
Some vehicles may exhibit noise, cold start stall, engine hesitation, sag, loss of power, or check engine light with codes 32 or 44. Condition(s) may be intermittent, but would typically be experienced in the first 5 minutes of engine/vehicle operation.

CAUSE:





Possible fuel starvation. The chart is provided to help during diagnosis activities.



Diagnostic Aids:

1. Oxygen sensor reading biased toward lean when the engine is under load.

2. Fuel pressure drops or does not increase by at least 5 psi when throttle moves from idle to part throttle.

3. Fuel integrator values steadily increasing under load.

4. Intermittent condition temporarily eased when accelerator pedal is released. Condition returns when accelerator pedal is reapplied.

5. Complete loss of fuel pressure.

CORRECTION:
Use Section 6E3 of the appropriate service manual to diagnose possible fuel system related problems. The vehicle may need to be operated under a load while monitoring fuel pressure to detect the problem. Make certain the fuel system is performing to specifications before other engine control system components are serviced.



PROCEDURE:
Follow procedures identified in the appropriate service manual, including section 8A or, for 1992 Achieva models specifically, see Dealer Technical Bulletin 92-T-84. For electrical intermittents, see the following Service Guild articles:

^ October 1991 issue of Service Guild, page 10.
^ June 1986 issue, page 68.
^ May 1988 issue, page 73.

Also see instruction in usage of required tool J 38125.