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 Saab 900 SPGFACTORY OEM SERVICE PROCEDURE
Fuel Pump Delivery Pressure
- Turn ignition off. Disconnect banjo coupling at inlet to fuel injection manifold. Connect a fuel pressure gauge using existing seals. Ensure pressure gauge hangs vertically. Turn ignition on. Pinch off fuel return line and check fuel pressure. When line is plugged, there should be an immediate increase in fuel pressure.CAUTION: DO NOT allow pressure to rise above 83 psi (5.8 kg/cm2 ).
- If fuel pressure does not increase, check for the following problems:
- At least 11.5 volts across fuel pump terminals
- Obstructed fuel lines
- Clogged fuel filter
- Fuel filter installed backward
- Defective relief valve in fuel pumpNOTE: If fuel filter has been installed backward, it must be replaced.
- After checking fuel pump pressure, turn ignition off. Go to FUEL PUMP DELIVERY FLOW test procedure (do not disconnect pressure gauge).
Factory Service Tools
Use the Manual With the Right Hardware
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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.