Motor mount CHEVROLET CAMARO 1982 Repair Guide

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 581

Fig. 1: Coolant temperature sensor. The in take air temperature sensor is similar
in appearance
IDLE AIR CONTROL (IAC) VALVE
OPERATION
Engine idle speeds are controlled by the ECM through the IAC valve mounted
on the throttle body. The ECM sends volt age pulses to the IAC motor windings
causing the IAC motor shaft and pintle to move IN or OUT a given distance
(number of steps) for each pulse (called counts). The movement of the pintle
controls the airflow around the throttle plat e, which in turn, controls engine idle
speed. IAC valve pintle position counts ca n be observed using a scan tool. Zero
counts correspond to a fully closed passage, while 140 counts or more
corresponds to full flow.
Idle speed can be categorized in 2 ways : actual (controlled) idle speed and
minimum idle speed. Contro lled idle speed is obtained by the ECM positioning
the IAC valve pintle. Resulting idle speed is determined by total air fl\
ow
(IAC/passage + PCV + throttle valve + ca librated vacuum leaks). Controlled idle
speed is specified at normal operating c onditions, which consists of engine
coolant at normal operating temper ature, air conditioning compressor OFF,
manual transmission in neutral or automatic transmission in D.
Minimum idle air speed is set at t he factory with a stop screw. This setting
allows a certain amount of air to bypas s the throttle valves regardless of IAC
valve pintle positioning. A co mbination of this air flow and IAC pintle positioning
allows the ECM to control engine idle speed. During normal engine idle
operation, the IAC valve pintle is positioned a calibrated number of steps
(counts) from the seat. No adjustment is required during routine maintenance.
Tampering with the minimum idle speed adjustment may result in premature
failure of the IAC valve or imprope rly controlled engine idle operation.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 669
1. Disconnect the pressure gauge. R
un the fuel line into a graduated
container.
2. Run the engine at idle until one pint of gasoline has been pumped. One
pint should be delivered in 30 seconds or less. There is normally enough
fuel in the carburetor float bowl to perform this test, but refill it if
necessary.
3. If the delivery rate is below the mini mum, check the lines for restrictions
or leaks, then r eplace the pump.
CARBURETORS
The V6 engine is equipped with the Ro chester E2SE carburetor, V8 engines
use the E4ME and E4MC. These carburet ors are of the downdraft design and
are used in conjunction with the CCC system for fuel cont rol. They have special
design features for optimum air/fuel mixt ure control during all ranges of engine
operation.
An electric solenoid in the carburetor controls the air/fu el ratio. The solenoid is
connected to an Electronic Control Module (ECM) which is an on-board
computer. The ECM provides a controllin g signal to the solenoid. The solenoid
controls the metering rod(s) and an id le air bleed valve, thereby closely
controlling the air/fuel ratio throughout the operating range of the engine.
MODEL IDENTIFICATION
General Motors Rochester carburetors ar e identified by their model code. The
first number indicates the number of ba rrels, while one of the last letters
indicates the type of choke used. These are V for the manifold mounted choke
coil, C for the choke coil mounted in the carburetor body, and E for electric
choke, also mounted on the carburetor. Model codes ending in A indicate an
altitude-compensatin g carburetor.
Because of their intricate nature and co mputer controls, the E2SE, E4ME and
E4MC carburetors should only be se rviced by a qualified technician.
PRELIMINARY CHECKS
The following should be observed befor e attempting any adjustments.
1. Thoroughly warm the engine. If the engine is cold, be sure that it reaches
operating temperature.
2. Check the torque of all carburet or mounting nuts and assembly screws.
Also check the intake manifold-to-cyli nder head bolts. If air is leaking at
any of these points, any attempts at adjustment will inevitably lead to
frustration.
3. Check the manifold heat control valve (if used) to be sure that it is free.
4. Check and adjust the choke as necessary.
5. Adjust the idle speed and mixture. If the mixture screws are capped,
don't adjust them unless all other c auses of rough idle have been
eliminated. If any adjustments are per formed that might possibly change

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 726
RELIEVING FUEL SYSTEM PRESSURE
1. Remove the fuse marked "Fuel Pu mp" from the fuse block in the
passenger compartment.
2. Crank the engine. Th e engine will start and run until the fuel supply
remaining in the lines is exhauste d. When the engines stops, engage the
starter again for three seconds to a ssure dissipation of any remaining
pressure.
3. With the ignition OFF, disconnect the negative battery cable to prevent
fuel discharge if the key is accidentally turned to the ON position.
Replace the fuse with the ignition OFF.
When disconnecting fuel lines, there ma y still be a small amount of fuel
released. Cover the fuel line connection wi th a shop cloth to collect the fuel,
then place the cloth in an approved container.
ELECTRIC FUEL PUMP
REMOVAL & INSTALLATION
The removal and installation procedures fo r the Crossfire injection system fuel
pump is identical to the Throttle Body In jection (TBI) system. Please refer to the
TBI fuel pump procedures earlier in this repair guide.
TESTING
The testing procedures for the Crossfire in jection system fuel pump is identical
to the Throttle Body Injection (TBI) syst em. Please refer to the TBI fuel pump
procedures earlier in this repair guide.
THROTTLE BODY
REMOVAL & INSTALLATION
FRONT UNIT
1. Relieve the fuel system pressure.
2. Remove the air cleaner assembly, noting the connection points of the
vacuum lines.
3. Detach the electrical connectors at the injector and the idle air control
motor.
4. Disconnect the vacuum lines from the TBI unit, noting the connection
points. During installation, refer to the underhood emission control
information decal for vacuum line routing information.
5. Disconnect the transmission det ent cable from the TBI unit.
6. Disconnect the fuel inlet (feed) and fuel balance line connections at the
front TBI unit.
7. Remove and discard the throttle cont rol rod retaining clip from the front
TBI throttle lever stud. A new clip must be used during reassembly.
8. Unbolt and remove the TBI unit.