How do you adjust the idle on a Toyota Tercel?

Answer 1

First, find the throttle body. If you do not know what you are looking for, the throttle body sits near the top of the engine. (On my 1994 model, it looks like a very large gray-metal hotdog bun). If you have trouble locating it, the accelerator pedal's cable attaches to it, as does plastic ducting coming from the engine's air cleaner, and you can easily see the accelerator pedal cable's spring-loaded cable return mechanism moving at the side of the throttle body as the accelerator pedal is pumped. With the motor off, ask someone to pump the accelerator pedal as you watch for movement, or try peeking under the open hood from inside the car as you pump the pedal yourself.

Once you have located the throttle body, view it from the passenger side of the car. Look for the top of the head of a standard, flat-head screw. (On my 1994, it is recessed about a quarter inch into the end of a tubular-shaped piece of metal about the size of my little finger that sits at the top of the throttle body where the air cleaner's ducting attaches.) This screw controls the engine's idle speed.

Use a medium-size flat-head screwdriver to slowly turn this screw. Be sure to make adjustments only when the engine is fully warm, and running. Clockwise rotation should slow the engine's idle speed, counter clockwise rotation should increase it. Although not necessary, using a tachometer will allow you to set a precise speed in revolutions per minute, "rpm". If your vehicle is not equipped with one on the dashboard, handheld tachometers exist, and can be attached to the engine. Tercels with manual transmissions suggest a warm-engine speed at idle of 750 rpm; those with automatic transmissions suggest a warm-engine speed at idle of 800 rpm.

Also, be aware that operating electrical components, such as headlights, brake lights, radio, fan, rear-window heater, and so on, will draw power from the motor, and can cause your engine's idle speed to slow. You may wish to set the idle speed while these devices are all in operation in order to insure an adequate idle speed when you are stopped in traffic, and operating these components. If you live in an area where emissions are checked before vehicle license tabs can be purchased, bring along a screwdriver to the testing station, in case you have set your idle speed in excess of the test's minimum idle-speed limit, generally 1100 rpm, and need to adjust it on the spot.

This applies to 1991-94 Tercel models.

** Below Added by James Young

The alternator is where power is drawn from, not the motor itself.