1982 CHEVROLET CAMARO fuel

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 729
17. Check the throttle position sensor voltage and adjust if necessary.
18. Perform the Minimum Idle and Thro
ttle Valve Synchronization adjustment
procedures.
INJECTOR REPLACEMENT
The removal and installation procedures fo r the Crossfire injection system's fuel
injector is identical to the Throttle Bo dy Injection (TBI) system. Please refer to
the TBI fuel injector procedures earlier in this repair guide.
ADJUSTMENTS
PRELIMINARY ADJUSTMENTS
The preliminary adjustments are performed if tampering with the idle speed or
synchronization is evident and when either of the throttle bodies or the manifold
cover have been replaced. They must be performed BEFORE the Minimum Idle
and Throttle Valve Synchronizing procedure.
THROTTLE VALVE SYNCHRONIZING
1. Turn BOTH front and rear unit throttle stop screws counterclockwise enough to break contact with the related throttle lever tangs.
2. Adjust the throttle synchronizing scr ew to allow BOTH throttle valves to
close. The throttle rod end bearing w ill move freely on the front unit
throttle lever stud when both valves are closed.
3. Turn the front unit th rottle stop screw clockwise slowly until it makes
contact with the throttle lever tang. Turn the screw clockwise an
additional
1/4 turn.
4. Turn the rear unit throttle stop screw clockwise slowly until it makes
contact with the throttle lever t ang. Turn the screw an additional
1/2 turn.

Fig. 1: Blocking the throttle levers

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 733
THROTTLE POSITION SENSOR (TPS)
An accurate digital voltmeter is
needed to perform this adjustment.
1. Remove the air cleaner.
2. Disconnect the TPS electrical connector.
3. Install three jumper wires betwe en the TPS and the TPS wiring terminal
connections.
4. Turn the ignition ON, engine stopped, measure the voltage between
terminals B and C.
5. The display should read between 0.45-0.60 volts.
6. Loosen the screws and rotate the TPS to obtain the correct voltage, if necessary.
7. Tighten the TPS screws and turn the i gnition OFF. Remove the jumpers.
8. Reconnect the wir ing to the TPS.
9. Install the air cleaner.

Fig. 5: TPS adjustment
FUEL PRESSURE REGULATOR
REMOVAL & INSTALLATION
The removal and installation procedures fo r the Crossfire injection system's fuel
pressure regulator is identical to t he Throttle Body Injection (TBI) system.
Please refer to the TBI fuel pressure r egulator procedures earlier in this repair
guide.
THROTTLE POSITION SENSOR (TPS)
REMOVAL & INSTALLATION
1. Remove the air cleaner.
2. Disconnect the electrical connector.
3. Remove the TPS attaching screws and lockwashers.
4. Remove the TPS.
To install:

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 735

Fig. 2: IAC valve installation
MULTI-PORT FUEL INJECTION SYSTEMS

SYSTEM DESCRIPTIONS
The Multi-Port Fuel Injection (MPFI or MFI) systems were first introduced on the
1985 models. They may be called different names (Port Fuel Injection-PFI,
Tuned Port Injection-TPI, Sequential Fuel Injection-SFI), however, all of the
systems are similar in operation.
The systems are controlled by an Elec tronic Control Module (ECM) which
monitors the engine operations and gen erates output signals to provide the
correct air/fuel mixture, ignition timing and idle speed. Input information to the
ECM is provided by the oxygen sens or, temperature sensors, detonation
sensor, mass air flow sensor and throttle position sensor. A system may use all
or some of these sensors, depending on the year and engine application. The
ECM also receives information concerning engine rpm, road speed,
transmission gear position, power steer ing and air conditioning status.
All of the systems use multiple injector s, aimed at the intake valve at each
intake port, rather than the centrally lo cated injector(s) found on the earlier
Throttle Body Injection (TBI) and Crossfir e Injection systems. The injectors are
mounted on a fuel rail and ar e activated by a signal from the electronic control
module. The injector is a solenoi d-operated valve which remains open
depending on the width of t he electronic pulses (length of the signal) from the
ECM; the longer the open time, the more f uel is injected. In this manner, the
air/fuel mixture can be precisely c ontrolled for maximum performance with
minimum emissions.
There are two different types of f uel management systems used on the multi-
port fuel injection engines. The mass air flow system and the speed density
system.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 736
The mass air flow systems measure the
mass of air that is drawn into the
engine cylinders, rather than just the vo lume. The sensor contains a hot-wire
sensing unit, which is made up of an electronic balanced bridge network.
Whenever current is suppli ed to the sensor, the bridge is energized and the
sensing hot-wire is heated. As the air enter s the mass air flow sensor, it passes
over and cools the hot wire. When the hot wire is cooled, it's resistance changes
and additional current is needed to k eep the bridge network balanced. This
increase in current is sent to the computer as a voltage signal and is used to
calculate the mass of the incoming air. The ECM uses this information to\

determine the duration of fuel injection pulse, ignition timing and EGR operation.
The speed density systems calculate the volume of air moving through the
intake. The ECM establishes the speed fact or through a signal from the ignition
module. The Manifold or Intake Air Temperature (MAT/IAT) and the Engine
Coolant Temperature (ECT) sensors work together to assure that proper
temperature information gets to the ECM wh ile the Manifold Absolute Pressure
(MAP) sensor monitors the changes in m anifold pressure which results from
changes in engine loading. These three se nsors contribute to the density factor.
Together, these inputs (engine speed, coolant temperature sensor, etc ...) are
the major determinants of the air/fuel mixture delivered by the fuel injection
system.
The following engines and fuel managem ent systems are covered in this
section:
• 1985-1989 2.8L MPFI - Mass Air Flow
• 1990-1992 3.1L MPFI - Speed Density
• 1985-1989 5.0L and 5.7L TPI - Mass Air Flow
• 1990-1992 5.0L and 5.7L TPI - Speed Density
Relieving Fuel System Pressure

1. Disconnect the negative battery cable to prevent fuel discharge if the key
is accidentally turned to the RUN position.
2. Loosen the fuel filler cap to reliev e the tank pressure and do not tighten
until service has been completed.
3. Connect J-34730-1 fuel pressure gauge or equivalent, to the fuel
pressure test valve. Wrap a shop towel around the fitting while
connecting the gauge to prevent spillage.
4. Place the end of the bleed hose into a suitable container and open the
valve to relieve the fuel system pressure.
ELECTRIC FUEL PUMP
REMOVAL & INSTALLATION
The fuel pump is part of t he fuel sender assembly located inside the fuel tank.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 737
1. Release the fuel syst
em pressure and disconnec t the negative battery
cable.
2. Drain the fuel tank, then raise and safely support the vehicle.
3. Remove the fuel tank from the vehicle.
4. Clean the area surrounding t he sender assembly to prevent
contamination of the fuel system.
5. Using tool J-24187 or equivalent, re move the sending unit retaining cam.
Remove the fuel sender and O-rings fr om the tank. Discard the O-rings.

Fig. 1: A special tool is usually availa ble to remove or install the fuel pump
locking cam
6. If necessary, separate the fuel pum p from the sending unit assembly.
To install: 7. If removed, install the fuel pump to the sending unit. If the strainer was
removed, it must be re placed with a new one.
8. Inspect and clean the O-ring mating surfaces.
9. Install a new O-ring in the groove around the tank opening. If applicable,
install a new O-ring on t he fuel sender feed tube.
10. Install the fuel sender assembly as follows: a. The fuel pump strainer must be in a horizontal position, and when
installed, must not block the travel of the float arm. Gently fold the
strainer over itself an d slowly position the sending assembly in the
tank so the strainer is not dam aged or trapped by the sump walls.
11. Install the retaining cam us ing tool J-24187 or equivalent.
12. Install the fuel tank assembly.
13. Lower the vehicle.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 738
14. Fill the fuel tank, tighten the f
uel filler cap and connect the negative
battery cable.
15. Turn the ignition switch to t he ON position for 2 seconds, OFF for 10
seconds, then back to the ON posit ion. Check for fuel leaks.

Fig. 2: Fuel pump assembly
TESTING 1. Relieve the fuel system pressure and check that there is an adequate
quantity of fuel in the tank.
2. Connect a fuel pressure gauge to the pressure connector fitting located
on the end of the fuel rail.

Fig. 3: Fuel pressure can be check ed using an inexpensive pressure/vacuum
gauge

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 739
3. Make sure the ignition switch has
been in the OFF position for at least 10
seconds and that all accessories are OFF.
4. Turn the ignition switch ON and the pump will run for about 2 seconds.
Note the system pressure with t he pump running, it should be between
40-47 psi.
The ignition switch may have to be cycled to the ON position more than once to
obtain maximum pressure. It is also norma l for the pressure to drop slightly
when the pump first stops, but it should then hold steady.
5. If the pressure is not as specified, verify that fuel pump operation is
heard in the tank.
6. If fuel pump operation is not heard, inspect the fuel pump relay and
wiring.
7. If fuel pump operation is heard, inspect the filter and lines for restriction.
8. Start the engine and make sure the pr essure decreases about 3-10 psi at
idle.
9. If fuel pressure does not decrease, inspect the fuel pressure regulator
and hose.
10. Disconnect the fuel pressure gauge.
THROTTLE BODY
REMOVAL & INSTALLATION 1. Disconnect the negative (-) battery c able and partially drain the radiator.
2. Remove the air inlet duct and unplug the IAC and TPS electrical connectors.
3. Label and disconnect the vacuum and coolant lines.
4. Disconnect the accelerator, thro ttle valve (transmission control) and
cruise control cables, as applicable.
5. Remove the throttle body attaching bolts, then separate the throttle body from the plenum.
6. Discard the gasket.
To install: 7. Install the throttle body to the plenum using a new gasket. Tighten the \
bolts to specification.
8. Engage the accelerator, throttle valve and cruise control cables, as
necessary. Make sure that the link ages do not hold the throttle open.
9. Connect the vacuum and coolant lines.
10. Install the air inlet duct and plug the IAC and TPS electrical connectors
into their sockets.
11. Connect the negative (-) battery cable and refill the radiator.
12. With the engine OFF, check to s ee that the accelerator pedal is free.
Depress the pedal to the floor and release.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 744
7. Start the engine and che
ck for proper operation.
FUEL INJECTORS
REMOVAL & INSTALLATION
Use care in removing injectors to prev ent damage to the electrical connector
pins and the nozzle. The fuel injector is serviced as a complete assembly only.
Since it is an electrical compon ent, DO NOT immerse it in a cleaner.
2.8L AND 3.1L ENGINES 1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure.
3. Remove the intake plenum and the fuel rail assembly.
4. Rotate the injector retaining clip to the unlocked position and remove the
injector. Discard the O-rings and the injector retaining clip.
Different injectors are calibrated for different flow rates. When ordering new
injectors, be sure to order the identical part number that is inscribed on the old
injector.
To install: 5. Lubricate the new O-ri ng seals with engine oil and install them on the
injector. Assemble a new reta ining clip on the injector.
6. Install the injector into the fuel ra il socket with the electrical connections
facing outward. Rotate the retaini ng clip to the lock position.
7. Install the fuel rail assembly.
8. Install the intake pl enum with new gaskets.
9. Tighten the fuel filler cap and connect the negative battery cable.
10. With the engine OFF and the igniti on ON, check for fuel leaks.

Fig. 1: Sectional view of a fuel injector