6000 V6-173 2.8L VIN W FI (1986)
Throttle Position Sensor: Technical Service Bulletins
Engine Controls - TPS Closed Throttle Specifications
Bulletin Number:
88-6-4
Reference Number:
816502
Publish Date:
10/87
Subject:
TPS INFORMATION AND SPECIFICATIONS
Models
1985-88 6000, FIREBIRD, SUNBIRD, FIERO,
Affected:
AND GRAND PRIX MODELS EQUIPPED WITH
2.8L V6 CPC ENGINES (VIN CODES W, S, 9)
Some 1985-87 Service Manual 6E3 Sections covering the 2.8L V6 PFI engines do not include information on the ability of the ECM to autozero 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 (VIN Codes W, S and 9).
When checking TPS output voltage at closed throttle, there are different specifications for the different 2.8L V6 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 on engines (VIN Codes W and S) if
the voltage is within the specified range and throttle valve angle reads 0%. The throttle position sensor on the 2.8L (VIN 9) engine is non-adjustable.
ACCEPTABLE CLOSED
ADJUSTMENT
YEAR
MODEL
ENGINE/CODE
THROTTLE RANGE (VOLTS)
SPECIFICATION
1985
A/J
2.8L
(VIN W)
0.35-0.67 Volts
0.55 +/- 0.1V
F
2.8L
(VIN S)
0.35-0.67 Volts
0.55 +/- 0.1V
P
2.8L
(VIN 9)
Less than 1.25 Volts
Non-Adj.
1986
A/J
2.8L
(VIN W)
0.35-0.67 Volts
0.55 +/- 0.1V
F
2.8L
(VIN S)
0.35-0.67 Volts
0.55 +/- 0.1V
P
2.8L
(VIN 9)
Less than 1.25 Volts
Non-Adj.
1987
A/J
2.8L
(VIN W)
0.35-0.7 Volts
0.55 +/- 0.1V
F
2.8L
(VIN S)
0.35-0.67 Volts
0.55 +/- 0.1V
P
2.8L
(VIN 9)
Less than 1.25 Volts
Non-Adj.
1988
A/J/W
2.8L
(VIN W)
0.35-0.7 Volts
0.55 +/- 0.1V
F
2.8L
(VIN S)
0.35-0.67 Volts
0.55 +/- 0.1V
P
2.8L
(VIN 9)
Less than 1.25 Volts
Non-Adj.
