Correctly setting the idle speed of the Ford Festiva's engine is critical to the proper operation of the vehicle. If the speed is too low, the engine will cease to run smoothly and could possibly stall out. If the idle is too high, unnecessary wear is placed on the engine components and the clutch. The idle air adjustment screw on the Festiva makes it much easier to adjust than most other fuel-injected vehicles.
Start the engine and place the automatic transmission in "Park" or the manual transmission in "Neutral." Firmly apply the parking brake. If the engine is not already warm, allow it to idle for five minutes to warm up before continuing.
Lift the hood and prop it open. Find the idle speed control valve, which is located to the right of where the plastic air intake pipe connects to the intake manifold. Remove the cap to expose the idle air adjustment screw.
Turn the screw with the flat-head screwdriver until the engine is idling at the desired rpm. The proper operating range for the 1.3-liter engine is between 830 and 870 rpm if equipped with automatic transmission, and between 680 and 720 rpm for a manual transmission. The range for the larger 1.6-liter engine is 800 to 900 rpm for both the automatic and manual transmissions. Anywhere within the operating range is acceptable.
