Engine - Poor Cold Driveability
Bulletin 86-6E-7Date Apr. '86
Ref. No. 86-099-6E
SUBJECT: POOR COLD DRIVEABILITY
MODELS AFFECTED: SOME 1986 CENTURYS, SKYLARKS AND SOMERSETS EQUIPPED WITH AUTOMATIC TRANSMISSIONS AND 2.5L ENGINES (VIN CODES "R AND U")
Some customer comments on poor cold driveability may be received on 1986 Centurys, Skylarks and Somersets equipped with 2.5L Engines (VIN Codes "R and U"). The comments may range from hesitations, sags, and stumbles, to engine miss.
These conditions may be caused by PROM calibrations that are too lean under some cold start driveaway conditions.
Should a vehicle with any of the above described cold driveability conditions be received, and normal service procedures do not correct the condition, the following service PROMS are available from GMWDD:
SERVICE
PROM MODEL ENGINE TRANS. AXLE
16062202 Century Coupe & 2.5L (VIN Code R) 3-Speed Auto. 2.39 Ratio
Sedan
16064305 Century Coupe, 2.5L (VIN Code R) 3-Speed Auto. 2.84 Ratio
Sedan, and Wagon
16060865 Skylark and 2.5L (VIN Code U) 3-Speed Auto. 2.84 Ratio
Somerset
Use applicable labor operation number and labor time for PROM replacement.