Engine - Stall/Sag or Hesitation After Cold Start
Number 87-6 (Gasoline)-33 Date 5/87Subject: STALL, SAG OR HESITATION AFTER COLD START
1986-87 FIREBIRD MODELS WITH 2.8L (VIN CODE S) MPFI ENGINE AND 4 SPEED AUTOMATIC TRANSMISSION
Some 1986-87 Firebird models with 2.8L MPFI engines and 4 speed automatic transmissions may experience one or more of the following conditions at 40 degrees (F) to 70 degrees (F) ambient temperatures:
^ Stall after cold start
^ RPM sag or stall when shifting from neutral to drive immediately after cold start.
^ Cold driveaway hesitation
To service this condition inspect for the following and repair as necessary.
1. Loose or leaking air duct between mass airflow (MAF) sensor and throttle body.
2. Low minimum idle speed. (Specification is 550 plus or minus 50 RPM in drive, automatic transmission.)
3. Openings in the EGR transfer tube.
If the condition persists, check PROM I.D. with scan tool. If the PROM I.D. is not any of the following numbers, replace the PROM with one of the service PROMS listed in the following chart.
Scan tool reading of PROM I.D. : 8419, 8420, 9891, 9901, 9911, 9921
SERVICE PROM APPLICATION
MODEL SALES AIR CONDITIONING SERVICE PROM
86 Firebird Federal Yes 16080020
Federal No 1228420
California Yes 16080015
87 Firebird Federal Yes/No 16080020
California Yes/No 16080015
NOTICE: THE ABOVE PROMS ARE FOR FIREBIRD MODELS WITH 2.8L PORT FUEL INJECTED ENGINES WITH 4 SPEED AUTOMATIC TRANSMISSIONS.
Use applicable labor time and labor operation numbers.