Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1981 Toyota StarletFACTORY OEM SERVICE PROCEDURE
Throttle Positioner: Tercel
- With engine coolant temperature below 122°F (50°C), start engine and increase engine speed to 3500 RPM. Disconnect vacuum hose from throttle positioner diaphragm A. Throttle positioner should now be set.
- Warm engine to normal operating temperature. Check and adjust idle speed if required. Disconnect and plug vacuum hoses from EGR valve and throttle positioner diaphragms A and B. Throttle positioner should now be set.
- With throttle positioner activated, engine speed should be 1400 RPM. If not, correct by turning throttle positioner adjusting screw making sure cooling fan is off. Reconnect vacuum hose to diaphragm B and see that engine returns to idle within 2-6 seconds.
- Reconnect vacuum hose to diaphragm A. Disconnect and plug vacuum hose located between TVSV and VTV 1 at VTV 1 and vacuum hose from diaphragm B. Increase engine speed to above 4500 RPM and plug VTV 1 pipe.NOTE: Ensure that stopper lever is separated from throttle positioner adjusting screw before plugging pipe.
- Release accelerator. Engine speed should be 2500-3000 RPM. Remove plug from VTV 1 pipe. Engine speed should return to 1400 RPM within 3-10 seconds. Reconnect all hoses.
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
Comes to youSame-day available12-month warranty
Get a Free QuoteNo obligation. See pricing before you book.