Poor Fuel Economy

Check for slipping clutch or transmission.
Check for dragging brakes.
Check odometer calibration.
Check vacuum system for leaks and routing.
Check air intake system. See TEST HU in SELF-DIAGNOSTICS - VILLAGER article.
Check fuel delivery system. See TEST HC in SELF-DIAGNOSTICS - VILLAGER article.
Check ignition system. See TEST JB in SELF-DIAGNOSTICS - VILLAGER article.
Check exhaust system. See TEST HF in SELF-DIAGNOSTICS - VILLAGER article.
Check for restricted exhaust system.
Check EGR system. See TEST HE in SELF-DIAGNOSTICS - VILLAGER article.
Check PCV system. See TEST HG in SELF-DIAGNOSTICS - VILLAGER article.
Check cooling system.
Vehicle load, driving habits, road and weather conditions can also effect fuel economy.