Engine Controls - Unstable/Rough Idle After Cold Start
86pontiac05Number 86-6(Gasoline)-59 Date 9/86
Subject: UNSTABLE OR ROUGH IDLE AFTER COLD START
1986 6000 AND 6000 LE MODELS WITH 2.8L V6 (VIN CODE W) MPFI ENGINE AND 4 SPEED AUTOMATIC TRANSMISSION
Some 1986 6000 and 6000 LE models with 2.8L V6 MPFI engines and 4 speed automatic transmissions may experience unstable or rough idle after cold start at ambient temperatures between 50~ to 70~ F.
To correct this condition inspect for the following and correct as necessary:
1. Loose or leaking air duct between mass airflow (MAF) sensor and throttle body.
2. Low minimum air rate and/or TPS setting.
3. Leaks in the EGR transfer tube and/or connections.
If the condition persists, replace the PROM with one of the following service PROMs:
MODELS SERVICE PROM
6000/6000 LE EMMISIONS HTR/AC PART NUMBER
CPE, SED Federal HTR 1228071
CPE, SED Federal AC 1228070
STA. WAG. Federal HTR 1228101
STA. WAG. Federal AC 1228085
CPE, SED California HTR 1228078
CPE, SED California AC 1228072
STA. WAG. California HTR 1228103
STA. WAG. California AC 1228102
NOTICE: The above PROMs are for6000 models, (except STE) 2.8L port fuel injected engines with 4 speed automatic transmissions.
Use applicable labor time and operation numbers.