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.
1990 Volvo 760 GLE, AW71LFACTORY OEM SERVICE PROCEDURE
Fuel Pump Pressure
- Remove panel under right side of dash. Remove fuel injection system relay. See Fig 1 . Crank engine for at least 5 seconds. If engine starts, let run until it dies. Before disconnecting, cover fuel line connector with shop towel to absorb any fuel spray.
- Connect a fuel pressure gauge between fuel line and injection manifold. Connect jumper wire between terminals No. 30 and 87/2 of fuel injection system relay connector. See Fig 2 . Fuel pressure should be 36-42 psi (2.5-3.0 kg/cm2 ).
- If pressure is too low, pinch off fuel return line and recheck pressure (DO NOT allow pressure to exceed 86 psi (6.0 kg/cm2 ). If pressure rises quickly, pump and lines are functioning correctly. Replace pressure regulator and recheck pressure.
- If pressure rises slowly, fuel filters or lines are blocked. If pressure does not rise, pump is defective.
- If fuel pressure is high, disconnect fuel return line from pressure regulator and blow into line. If line is open, pressure regulator is defective and should be replaced.
- Pressure may also be checked with engine off and fuel gauge connected. Attach a hand-held vacuum pump to pressure regulator. Line pressure should decrease as vacuum is applied to regulator.
- With 12 volts applied, pump volume should be 1.22 qts. (1.08L) in 30 seconds.
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.