Idle Enrichment System Diagnosis

IDLE ENRICHMENT SYSTEM
1. Warm engine to normal operating temperature, then remove air cleaner. Do not cap any fittings opened by hose removal as leakage is needed for testing.
2. Disconnect hose from idle enrichment diaphragm at plastic connector and remove connector from hose.
3. Start engine and place fast idle speed screw on slowest speed step of fast idle cam.
4. Connect 3-4 feet of hose to enrichment diaphragm.
5. Apply vacuum to other end of hose and observe engine speed change. If engine speed changes when vacuum is applied, the idle enrichment system is operating properly. If engine speed does not change when vacuum on Holley carburetors, or proceed to steps 6 and 7 if equipped with Carter carburetor.
6. Cover air inlet passage and observe engine speed change. If speed changes, the diaphragm is leaking or the air valve is stuck closed.
7. Clean valve and repeat step 5. If not operating properly, replace diaphragm.

TIME DELAY SYSTEM
On some vehicles, the timing module and solenoid valve control both EGR delay and idle enrichment duration.
1. Check wiring for proper connections and correct as necessary.
2. With ignition switch off, disconnect connector from time delay solenoid valve.
3. Connect a test light across connector terminals.
4. Start engine. Test light should go on and remain on for 60 seconds after engine starts.
5. If light does not go on, remains on indefinitely, or does not remain on the amount of time specified in step 4, replace timer. In order to avoid overloading of timer, the tester current draw should not exceed .5 amps.

COOLANT CONTROL IDLE ENRICHMENT (CCIE) VALVE
1. Check vacuum hoses for proper routing and make sure that valve is properly installed. Also make sure that engine coolant is at proper level.
2. Disconnect molded connector from valve and connect a 1/8 inch inside diameter hose to bottom port of valve.
3. With engine coolant at 75° F. or less, blow air through hose. If air does not flow freely, replace valve.
4. Start engine and warm to normal operating temperature, then using an external vacuum source, apply 10 inches Hg to valve. If vacuum level drops more than one inch in 15 seconds, replace valve.