The CCIE system is used on most 1975 and later models with automatic transmissions. The system consists of a vacuum-operated valve built into the carburetor, which shuts off the idle circuit air bleeds when vacuum is supplied to its diaphragm.
Depending upon engine application, vacuum is either routed through a coolant controlled vacuum valve or an EGR vacuum control solenoid.
Vacuum is passed to the valve diaphragm below a predetermined temperature, and on models with an EGR control solenoid for only 35 seconds after the engine is started. The CCIE valve action closes off the air bleed passages, which richens the mixture, and allows a smoother cold idle.
Idle Enrichment System
The purpose of the idle enrichment system is to reduce cold engine stalling by use of a metering system related to the basic carburetor instead of the choke. The system enriches carburetor mixtures in the curb idle and fast idle area.
A small vacuum-controlled diaphragm mounted near the top of the carburetor controls idle system air. When control vacuum is applied to the diaphragm, idle system air is reduced. Air losses strengthen the small vacuum signal within the idle system and fuel flow increases. As a result of more fuel and less air, the engine will idle better when cold.
To test the system, proceed as follows:
- Run the engine to normal operating temperatures.
- Remove the air cleaner, but do not cap any of the vacuum fittings opened by hose removal. The vacuum leakage is needed for the test.
- Disconnect the hose to the idle enrichment diaphragm at the plastic connector. Remove the plastic connector from the carburetor hose.
- With the engine running, place the fast idle screw on the lowest step of the fast idle cam.
- Connect three or four feet of hose to the enrichment diaphragm hose with a suitable connector.
- Use a hand vacuum pump and apply vacuum to the hose. Listen for a change in engine speed. If the engine speed can be controlled by vacuum, then the system is OK. If the speed cannot be controlled, replace the valve assembly (Holley carburetors) or proceed to the next step (Carter carburetors).
- Place a finger over the air inlet passage and listen for an engine speed change. If you can control engine speed this way, the diaphragm is leaking or the air valve is stuck open. If speed cannot be controlled this way, the air valve is stuck closed. In either case, clean the air valve, and repeat step six. If speed control is still absent, replace the diaphragm.
- First make sure the vacuum hoses are routed correctly and the engine coolant level is correct.
- Disconnect the molded connector from the valve. Attach a 1 / 8 in. hose to the bottom port on the valve.
- Run the engine to normal operating temperature.
- With the top tank warm to the touch (but no warmer than 75°F.), blow through the hose. If it is not possible to blow through the valve, then it is defective and must be replaced.
- Attach a vacuum pump to the bottom port of the valve. Apply 10 in. of vacuum. If the vacuum level drops more than one inch in 15 seconds, replace the valve.