Ford Electronic Engine Control III (EEC-III) with feedback carburetor is used on 351" models in all states and on 302" Ford and Mercury for California. All 302" Lincoln and Mark VI models use EEC-III with Electronic Fuel Injection (EFI). EEC-III replaces EEC-I and EEC-II systems used earlier.

The EEC system consists of an Electronic Control Assembly (ECA), several sensors located on the engine or in the various engine systems, special actuators governed by the ECA, and various connecting electrical and vacuum lines. This system adjusts the engine to the best settings for various conditions of load, speed, temperature and altitude by controlling the following functions:

Ignition Timing
Carburetor Air/Fuel Ratio
Engine Speed At Idle
Exhaust Gas Recirculation (EGR) Flow Rate
Secondary (Thermactor) Air Flow Rate
Fuel Evaporation Canister Purging
NOTE: There are approximately 25, 000 351" engines in 1980 vehicles with the EEC-II system. These engines are easily identified by the SILVER engine decal and by a red vinyl tag on the harness near the EEC module connector in the engine compartment which is marked "EEC-II". EEC-III vehicles have a GOLD tone engine decal. The primary difference is in Test Sequence which is covered in the Tester Operator's Manual.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Electronic Engine Control III: Description

Use the Manual With the Right Hardware

When to See a Mechanic