
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 695
Fig. 27: Idle mixture needle plug removal
E4ME CARBURETORS (ELECTRIC CHOKE) 1. Using tool J-29030, BT-7610-B, or equivalent, turn both idle mixture
needles clockwise until they are lightly seated, then turn each mixture
needle counterclockwise 3 turns.
2. Reinstall carburetor on engine using a new flange mounting gasket, but
do not install air cleaner and gasket at this time.
3. Disconnect the vacuum hose to canister purge valve and plug it.
Readjust the idle air bleed valve to finalize correct dwell reading.
4. Connect the positive lead of a dwell me ter to the mixture control solenoid
test lead (green connector). Connect the other lead to ground. Set the
meter to the 6 cylinder position.
5. Start engine and run unt il fully warm, then repeat the idle air bleed valve
adjustment.
6. If unable to set dwell to 25-35 degrees and the dwell is below 25
degrees, turn both mixture needles counter clockwise an additional turn. If
dwell is above 35 degrees, turn both mixture needles clockwise an
additional turn. Readjust idle air bleed valve to obtain dwell limits. Repeat
as needed.
7. After adjustments are complete, seal the idle mixture needle openings in
the throttle body, using silicone sealant, RTV rubber, or equivalent. The
sealer is required to discourage unnecessary adjus tment of the setting
and to prevent fuel vapor loss in that area. Reconnect canister vacuum
hose.
8. On vehicles without an Idle Load Co mpensator (ILC), adjust curb idle
speed if necessary.
9. Check, and if necessary, adjust fa st idle speed as described on Vehicle
Emission Control Information (VECI) label.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 696
Fig. 28: Lean mixture and idle mixture screw adjustment
E4MC CARBURETOR (HOT AIR CHOKE) 1. Using tool J-29030-B, BT-7610-B, or equivalent, turn each idle mixture
needle clockwise until lightly seated, then turn each mixture needle
counterclockwise 3 turns.
2. Reinstall carburetor on engine, using a new flange mounting gasket, but
do not install air cleaner or gasket at this time.
3. Disconnect vacuum hose to c anister purge valve and plug it.
4. Connect the positive lead of a dwell me ter to the mixture control solenoid
test lead (green connector). Connect the other lead to ground. Set the
meter to the 6 cylinder position.
5. Start engine and allow it to reac h normal operating temperature.
6. While idling in D ( N for manual transmission), adjust both mixture
needles equally, in
1/8 turn increments, until dwell reading varies within
the 25-35 degree range, attempting to be as close to 30 degrees as
possible.
7. If reading is too low, turn mixtur e needles counterclockwise. If reading is
too high, turn mixture needl es clockwise. Allow time for dwell reading to
stabilize after each adjustment.
After adjustments are complete, seal t he idle mixture needle openings in the
throttle body, using silicone sealant, RTV rubber, or equivalent. The sealer is
required to discourage unnece ssary readjustment of the setting and prevent fuel
vapor loss in that area.
8. On vehicles without a carburetor -mounted Idle Load Compensator (ILC) ,
adjust curb idle speed if necessary.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 698
5. Disconnect and plug hose to canister purge port.
6. Disconnect and plug hose to idle load compensator.
7. Back out idle stop screw
on carburetor 3 turns.
8. Turn air conditioning OFF.
9. Block drive wheels, set parki ng brake, place transmission in P, start and
warm engine to normal operating temperature. Make certain choke is
OPEN .
10. With engine RUNNING place transmission in D and idle load
compensator fully extended (no vacuum applied). Using tool J-29607, or
equivalent, adjust plunger to obtain 650-750 rpm. Locknut on plunger
must be held with a wrench to prevent damage to guide tabs.
11. Measure distance from the locknut to tip of the plunger. This distance
must not exceed 1 in. (25mm). If it does check for low idle condition.
12. Reconnect vacuum hose to idle load compensator and observe idle
speed.
13. Idle speed should be between 425-475 rpm in D.
14. If idle speed is correct no further adjustment is necessary, proceed to the
next step. If idle speed is still incorrect continue as follows:
It may be necessary to remove the idle load compensator from the engine
unless a hex key wrench is m odified to clear obstructions.
a. Stop engine, remove rubber cap from the center outlet tube.
b. Using a 0.90 in. (23mm) hex wrench, insert through open center tube to
engage idle speed adjusting screw.
c. If idle speed was low, turn t he adjusting screw counterclockwise
approximately 1 turn for every 85 rpm low. If idle speed was high turn
screw 1 turn for every 85 rpm high.
15. Disconnect and plug vacuum hose to the idle load compensator.
16. Using a hand pump, apply vacuum to the idle load compensator until fully
retracted.
17. Adjust the idle stop screw on carburetor float bowl to obtain 450 rpm in
D .
18. Place transmission in P and stop engine.
19. Reconnect the idle load compensator.
20. Reconnect all vacuum hoses.
21. Install air cleaner and gasket. Remove wheel blocks.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 724
•
Type 2: Compress retaining spring from valve while turning valve
in with a clockwise motion. Return spring to original position with
straight portion of spring end aligned with flat surface of valve.
On IAC valves that have already been in service, do not push or pull on the
valve pintle. The force required to move the pintle may damage the threads on
the worm drive.
5. Use a new gasket or O-ring and install the IAC valve into the throttle body.
6. Allow the ECM to reset the idle air control valve using the procedure
described earlier in this section.
Fig. 1: Idle air control valve installation
CROSSFIRE INJECTION SYSTEM
SYSTEM DESCRIPTION
The Model 400 Electronic Fuel Injection (EFI) system is a computer controlled
system that uses a pair of Throttle Body Injection (TBI) units, which are
mounted on a single manifold cover on t he 5.0L (VIN 7) engine. Since each TBI
feeds the cylinders on the opposite side of the engine, the system has acquired
the name of Crossf ire Injection.
Fuel is supplied, by an electric fuel pum p located in the fuel tank, to the front
TBI fuel accumulator. From the accumulator, it is carried to the rear TBI fuel
pressure regulator by a c onnecting tube. Unused fuel is sent to the fuel tank
through a separate return line.

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 751
13. Lubricate a new outlet tube 0-ring and in
stall it on the end of the tube.
14. Connect the regulator base to the fuel outlet tube, then to the fuel rail.
15. Finger-tighten the base-to-rail screw.
16. Install the pressure regulator br acket. Finger-tighten the screws only.
17. Lubricate a new rear crossover tube O-ring and install it on the end of the
tube.
18. Install the rear crossover tube to the regulator base.
19. Install the crossover tube reta iner and finger-tighten the screw.
20. Tighten all attaching screws to 44 inch lbs. (5 Nm).
21. Install the fuel rail assembly.
22. Temporarily connect the negative battery cable. a. With the engine OFF and the igniti on ON, check for fuel leaks.
b. Disconnect the negative battery cable.
23. Install the intake plenum and runners.
24. Connect the negative battery cable.
IDLE AIR CONTROL VALVE
REMOVAL & INSTALLATION 1. Unplug the electrical connector from idle air control valve.
2. Remove the idle air control valve.
To install: 3. Before installing the idle air contro l valve, measure the distance that the
valve is extended. Measurement s hould be made from the motor housing
to the end of the cone. It should not exceed 28.5mm (1
1/8 in.), or damage
to the valve may occur when installed.
4. On 1985-1992 models, identify the replacement IAC valve as being
either Type 1 (with collar at electric terminal end) or Type 2 (without
collar). If measuring distance is great er than specified above, proceed as
follows:
• Type 1: Use finger pressure to slowly retract the pintle.
• Type 2: Compress retaining spring from valve while turning valve
in with a clockwise motion. Return spring to original position with
straight portion of spring end aligned with flat surface of valve.
On IAC valves that have already been in service, do not push or pull on the
valve pintle. The force required to move the pintle may damage the threads on
the worm drive.
5. Use a new gasket or O-ring and install the IAC valve into the throttle body.
6. Allow the ECM to reset the idle air control valve using the procedure
described earlier in this section.