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 Ford Bronco II RWD, Standard, M5OD-R1FACTORY OEM SERVICE PROCEDURE
Fuel Pump Pressure
NOTE:
For fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS
article.
- Remove fuel tank cap. Using Fuel Pressure Gauge (T80L-9974-B), release pressure from system at pressure relief valve (Schrader valve) on fuel injection manifold rail. This is the same valve at which pressure is measured when pressure testing the system.
- An alternate method of relieving fuel system pressure is to disconnect the inertia switch and crank engine for 15-20 seconds. See INERTIA SWITCH in this article for inertia switch location.
- To test fuel pump pressure, turn key off and install fuel pressure gauge as described in step 1). Install test lead to fuel pump test lead of self-test connector. See Fig 1 . Turn key to RUN position. Ground test lead to cause fuel pump to operate. Determine if pressure is within specification.
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.