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.
1986 Chevrolet Caprice Brougham, 4.3 Z, 700R4/MD8FACTORY OEM SERVICE PROCEDURE
Fuel System Pressure Test
CAUTION:
Always relieve residual pressure in fuel delivery system before opening system.
- To relieve any residual system pressure, remove "FUEL PUMP" fuse from fuse block in passenger compartment. Crank engine. Engine will start and run until fuel supply remaining in fuel lines is used. Engage starter again for about 3 seconds to make sure all fuel is out of lines. Turn ignition off and replace fuse.
- Remove air cleaner and plug air cleaner (THERMAC) vacuum port on throttle body. Remove steel fuel line between throttle body and fuel filter. When removing fuel line, always use 2 wrenches to prevent damage. Install Fuel Pressure Gauge (J-29658) between throttle body and fuel filter.
- Start vehicle and observe fuel pressure reading. Fuel pressure should be 9-13 psi (.6-.9 kg/cm2 ). If fuel pressure is not within specifications, go to CHART A-5 or CHART A-6 in this article. 4) Relieve residual pressure as described in step 1). Remove fuel pressure gauge. Reinstall steel line between filter and throttle body. Start vehicle and watch for leaks. Remove plug from throttle body thermal vacuum port and reinstall air cleaner.
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.
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