Regal V6-173 2.8L (1988)
Throttle Position Sensor: Technical Service Bulletins
Engine Controls - Closed Throttle TPS Specifications
Bulletin:
88-6E-3
Date:
Nov., '87
Ref. No.: 88-016-6E
Corp. Ref. No.: 816502
SUBJECT:
TPS INFORMATION AND SPECIFICATIONS
MODELS AFFECTED: 1985-88 BUICKS EQUIPPED WITH LB6 2.8L V-6 ENGINES (VIN CODE W)
Some 1985 through 1987 Service Manual 6E3 Sections covering the 2.8L V-6 PFI engines do not include information on the ability of the ECM to
auto-zero throttle position sensor (TPS) reference voltage. Auto-zero can be described as the ability of the ECM to determine a closed throttle position
any time TPS voltage is within a specified range (see chart below). As long as the TPS reference voltage is within that range, the system will function
properly. This capability is found on all 2.8L PFI engines.
When checking TPS output voltage at closed throttle, there are different specifications for the different 2.8L V-6 applications. "Scan" tools having the
ability to also read the throttle valve angle should read 0% when the throttle valve is closed. Do NOT adjust the TPS if the voltage is within the specified
range and throttle valve angle reads 0%.
ENGINE/
ACCEPTABLE CLOSED
ADJUSTMENT
YEAR
MODEL
CODE
THROTTLE RANGE (VOLTS)
SPECIFICATION
1985
Skylark
2.8L (VIN W)
0.35-0.67 Volts
0.55 +/- 0.1V
1987
Century
2.8L (VIN W)
0.35-0.7 Volts
0.55 +/- 0.1V
1988
Century/ 2.8L (VIN W)
0.35-0.7 Volts
0.55 +/- 0.1V
Regal
