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.
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HOMESERVICE MANUALSTOYOTA1990TERCEL BASE, 2D COUPE, STANDARDREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCESYSTEMENGINE CONTROLS - SYSTEM/COMPONENT TESTS - EFITHROTTLE CONTROLSDASHPOT CONTROL SYSTEM (FEDERAL)
1990 Toyota Tercel Base, 2D Coupe, Standard
Dashpot Control System (Federal)
1990 Toyota Tercel Base, 2D Coupe, StandardSECTION Dashpot Control System (Federal)
- Engine must be at normal operating temperature. Check idle speed and adjust if necessary. Remove cap, filter and separator from dashpot. See Fig 1.
- Start engine. Maintain engine speed at specified testing RPM. See DASHPOT TESTING RPM table. Plug Vacuum Transmitting Valve (VTV) hole with your finger. See Fig 1.
- Release throttle. Dashpot should be extended and dashpot setting RPM should be as specified. See DASHPOT TESTING RPM table. If idle speed is incorrect, adjust dashpot. See Fig 2.
- To check VTV operation, run engine at dashpot testing RPM for a few seconds. Plug the VTV hole with your finger. Release throttle. Uncover plugged hole. Engine should return to idle in about one second.
- Install dashpot separator, filter and cap. Install filter with coarser surface facing outward.
DASHPOT TESTING RPM
| Application | Testing RPM | (1) Dashpot Setting RPM | ||
|---|---|---|---|---|
| Tercel | 2500 | 1500 | ||
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RENDER: 1.0x
NO RELATED
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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.