Initial Inspection and Diagnostic Overview

In order that the ignition and fuel systems function properly, all electrical, vacuum or air hose connection must be complete and tight.
Terminals in electrical connections must lock together. Look for connectors that are not fully plugged into each other or terminals that are not fully plugged into the insulator.
All hoses must be fully and firmly fitted at their connections. Look for hoses that are not fully plugged on or are pinched and cut.

The following must be checked before proceeding with the diagnostic procedure.

1. IGNITION SYSTEM COMPONENTS
A. Connectors at Computer.
B. Start and run pickup coil connectors at distributor.
C. Spark plug wires.
D. Coil wire (cap and coil connections).
E. Connectors at coil.
F. Connectors at starter relay.
G. Connector at detonation sensor. (5.2L)

2. FUEL CONTROL SYSTEM
A. Connector at engine coolant sensor located in the front of the intake manifold.
B. Connector at charge temperature sensor and switch located in the rear of the intake manifold.
C. Connector at oil pressure switch.
D. Connector and choke control.
E. Connectors at carburetor harness.
F. Carburetor ground switch.
G. Connectors at air switching and EGR solenoids.
H. Engine harness to main harness connector.
I. Battery cables.
J. Battery ground on engine.
K. Engine to firewall ground strap.
L. Oxygen sensor connector.

3. PCV SYSTEM
A. Hose between carburetor and PCV valve.
B. PCV valve plugged into valve cover grommet.
C. Correct PCV valve. Should be White in color.

4. COMPUTER
A. Hose between vacuum transducer and carburetor.
B. Air intake hose.

5. EGR SYSTEM
A. Hose between carburetor and EGR amplifier.
B. Hose between intake manifold and EGR amplifier.
C. Hose between EGR amplifier and EGR solenoid.
D. Hose between EGR solenoid and EGR valve.
E. Hose between EGR amplifier and vacuum reservoir (3.7L only).

6. AIR SWITCHING SYSTEM
A. Hose between intake manifold and air switching solenoid.
B. Hose between air switching solenoid and air switching/relief valve.
C. Hose between air switching/relief valve and plumbing to exhaust manifolds.
D. Hose between air switching/relief valve and plumbing to catalyst.

7. EVAPORATIVE CONTROL SYSTEM
A. Hose between carburetor bowl vent and canister.
B. Hose between canister and air cleaner.
C. Hoses between canister and air pump.
D. Hose between canister and fuel tank line (this hose has a vapor bypass valve in it).
E. Hose from carburetor bowl vent to canister.
F. Hose from carburetor manifold vacuum nipple to canister(s).
G. Hose between canister(s) and CVSCC valve.
H. Hose between CVSCC valve and vacuum TEE connector in EGR vacuum hose.

8. CHOKE SYSTEM
A. Hose between carburetor and vacuum kick diaphragm. Some high altitude vehicles have a delay valve in this hose.

9. HEATED AIR DOOR SYSTEM
A. Hose between carburetor and air temperature sensor. Some models may have hose connected to a tee rather than carburetor.
B. Hose between air temperature sensor and door diaphragm.
C. Hose between air cleaner and exhaust manifold heat stove.

10. POWER BRAKES AND/OR SPEED CONTROL
A. Hose between carburetor and power brake booster. Some models have a charcoal filter in this hose.
B. Hose between power brake booster and speed control servo.

11. HEATER/AC SYSTEM
A. Vacuum hose at water valve.
B. Vacuum supply hose to instrument panel control.

12. VAPOR CONTAINMENT DOOR (Where Applicable)
A. Hose between door diaphragm and vacuum tee connector. This hose has a delay valve in it.