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.
1991 Toyota Land CruiserFACTORY OEM SERVICE PROCEDURE
Fuel Pressure-Up System
- Ensure coolant temperature switch is operating correctly. Switch is in side of engine block and has a Pink wire attached. There should be no continuity between switch terminal and body when coolant temperature is less than 208°F (98°C). There should be continuity between switch terminal and body when coolant temperature is more than 220°F (105°C).NOTE: The ECU uses signal from coolant temperature switch to control the ground circuit for fuel pressure-up vacuum switching valve.
- Fuel pressure-up system is controlled by ECU through a vacuum switching valve. The vacuum switching valve is fed current through the EFI main relay when the ignition is turned on. ECU controls the ground circuit. ECU will activate vacuum switching valve for 90-180 seconds when restarting engine at normal operating temperature.
- Vacuum switching valve is located on left fender (rear most vacuum switching valve). Check operation of vacuum switching valve using Fig 1 as a reference.
Factory Service Tools
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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.