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 Geo Prizm LSi, StandardFACTORY OEM SERVICE PROCEDURE
Fuel Pressure Release
- Loosen fuel tank cap to release fuel tank pressure. Disconnect electrical connector on circuit opening relay attached to ECM, located under radio in instrument panel center console. Start engine and allow to idle until engine dies. Crank engine for approximately 10 seconds to ensure residual fuel line pressure is released. Disconnect negative battery cable.
- Slowly loosen cold-start injector line bolt at fuel rail. Use shop towel to absorb fuel escaping as fuel pressure is released. When fuel is fully released, tighten cold-start injector line bolt to 13 ft. lbs. (18 N.m). Reconnect circuit opening relay and negative battery cable.
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.
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