Initial Inspection and Diagnostic Overview
Visual Checks1. Check vacuum lines for obstructed, cracked or broken hoses and loose or improper connections. Correct as necessary.
2. Check electrical harness for the following:
a. Broken, disconnected, or frayed wires and insulation.
b. Terminals not completely seated in connectors.
c. Corrosion on terminals.
d. Loose or improper connections.
3. Check coolant level and correct to required quantity as needed.
Pre-Test Conditions
1. Place transmission in Neutral or Park.
2. Apply parking brake and block drive wheels.
3. Turn off all accessories.
4. Leave vacuum hoses attached to air cleaner.
5. Start engine and allow to reach normal operating temperature. Upper radiator hose should be hot and pressurized. If engine will not start, refer to "Test 1-No Start Test" under "Subroutines."
6. With the engine running, use voltmeter to make sure there is power to the choke unit. On 1982 V6 engine, 6.5-7.5 volts DC are required. On 1982 V8 engine, 10-12 volts DC are required.
Fig.3 - Voltmeter & Jumper Wire Connections:
Fig.4 - Canister Control Valve:
Preparation For Testing
1. Turn ignition key off.
2. Connect a jumper wire from self-test trigger to ground on self-test connector, Fig. 3.
3. Connect voltmeter from battery positive terminal to self-test output on self-test connector, Fig. 3. Set voltmeter to DC volt range from 0-15 volts.
NOTE: Meter may read battery voltage at this time.
4. Inline 4 & 6 cyl. engines:
a. On 1981 engines with a vacuum purge valve, disconnect the hose from the canister control valve to the PCV valve and plug it, Fig. 4. On 1982 engines with a vacuum purge valve, disconnect the hose from the carbon canister to the purge valve, but do not plug the hose, Fig. 4.
b. Check carburetor linkage to see that it is not set with the fast idle cam engaged, and check that choke is fully open.
c. On 2.3 L engines marked with GK on the MCU identification tag, remove the cap from the anti-backfire valve. Recap after completing Functional Test.
5. V6 & V8 engines:
a. Remove PCV valve from valve cover.
b. Tee a vacuum gauge to the canister purge solenoid valve hose on the carbon canister side of the hose.
c. On 4.2L engines with vacuum delay valve, uncap the restrictor on Thermactor Diverter Vacuum Control line. Recap after completing Functional Test. On 5.8L engines with vacuum delay valve, uncap restrictor on the Thermactor Bypass Vacuum Control line. Recap after completing Functional Test.