Engine - Poor Performance, Poor Idle, and Engine Surge
86chevy10Number: 86-122
Section: 6D
Date: JULY, 1986
Sublect: THROTTLE POSITION SENSOR
HEAT SHIELD KIT
Model and Year:
1982-1986 CELEBRITY WITH 2.5L (VIN CODE R) ENGINE 1982-1986 CAMARO WITH 2.5L (VIN CODE 2) ENGINE 1985-1986 M VAN WITH 2.5L (VIN CODE E) ENGINE 1985-1986 S/T TRUCK WITH 2.5L (VIN CODE E) ENGINE
TO: ALL CHEVROLET DEALERS
Customer comments of reduced engine performance, poor idle, and engine surge, may be received on the above listed vehicles equipped with 2.5L L4 engines.
NEW HEAT SHIELD SERVICE KIT:
After a vehicle has been accurately diagnosed as having an intermittent electrical signal from the throttle position sensor, replace the sensor with AC TPS Service Kit, P/N 17078274. At the same time, remove the factory installed TPS heat shield attached by the EGR bolt and replace it with a new heat shield service kit, P/N 17111750 (Figure 1). The contents of the service kit are:
DESCRIPTION
Screw assemblies - 2 each (hex head) Heat Shield - Stainless steel Graphics - Instruction sheet
Whenever a new 300 Series TBI is purchased from WDDGM and it is not complete with the AC TPS and the stainless steel heat shield it must be retro-fitted to include the new service parts.
Use applicable labor time and labor operation numbers.
NEW HEAT SHIELD SERVICE KIT:
RECOMMENDED PROCEDURE:
1. REMOVE AIR CLEANER ASSEMBLY.
2. REMOVE AND DISCARD OLD HEAT SHIELD ATTACHED TO
EGR MOUNTING BOLTS, BY REMOVING ONE BOLT ONLY.
3. REMOVE AND DISCARD OLD TPS ATTACHING SCREWS.
4. INSTALL NEW TPS (1) AND HEAT SHIELD (3) USING
NEW ATTACHING SCREWS (2) PROVIDED WITH TPS
HEAT SHIELD SERVICE KIT.
^ TIGHTEN ATTACHING SCREWS TO 18 IN. LBS. (2.0 N-m).
5. INSPECT TPS CONNECTOR LEAD PER BULLETIN 86-8-10.
Note: This is a Pontiac Bulletin, see below.
6. INSTALL AIR CLEANER ASSEMBLY.
Number 86-8-10 Date 2/86
Subject: TPS WIRING MAY BE RUBBED THRU ON 1984-1986 FIERO
1984 THRU 1986 FIERO WITH 2.5L ENGINE
TPS Wiring:
CONDITION:
The wires leading to the throttle position sensor (TPS) may be rubbed thru on 1984 to 1986 Fiero with 2.5L engine. This may lead to intermittent TPS operation, resulting in poor driveability.
CAUSE:
The nylon conduit around the wires may rub through the insulation.
CORRECTION:
Perform the following operation any time a TPS is replaced, or an intermittent TPS condition is found:
1. Disconnect negative battery cable.
2. Remove air cleaner.
3. Disconnect MAP sensor and TPS connectors, to allow access to harness.
4. Open conduit and remove TPS leads. Repair any damage to the wires or insulation found. Wrap the TPS leads with three (3) layers of electrical tape, all the way to the connector (see illustration).
5. Replace wires in conduit, and reconnect TPS and MAP sensor leads.
6. Replace air cleaner, and reconnect negative battery cable.