For 1990-2009 cars

# FUEL PUMP DRIVEABILITY ISSUE DIAGNOSTIC INFORMATION

#### 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 following chart is provided to help during diagnosis activities.

#### Note: Certain recognized problems associated with 1992 Achieva's were corrected effective with vehicles built after March 1992. See Dealer Technical Bulletin 92-T-84. This chart does not include all Oldsmobile vehicles.

The "Where Most Common" column lists vehicles most likely to exhibit the condition listed.

Other vehicles could exhibit similar conditions.

#### 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.

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.