Regal V6-173 2.8L (1988)
DRIVEABILITY AND EMISSIONS - FUEL INJECTION (PORT)
The following service information revises the recommended diagnostic procedure (reference sheet 6E3-B [symptoms] of the Service Manual) for rough,
unstable or incorrect idle and stalling at idle for 1988 Buicks equipped with a 2.8L V-6 MPFI engine (VIN Code W).
A base idle RPM adjustment is not required and should not be performed on 1988 vehicles.
The following information provides an explanation for the above revision.
All 2.8L MPFI V-6 engine calibrations for 1988 production and 1987 service include a feature which stores in Electronic Control Module (ECM)
memory the Idle Air Control Valve (IAC) position at which the engine idles. Each vehicle will have a unique value, depending on the throttle body base
air rate setting, deposit buildup, etc. The IAC position information is continuously updated, during vehicle operation, and stored in the ECM "keep alive"
