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.
Fuel Injection System - Diesel: Description
General Motors V6 and V8 engines use a mechanical high pressure rotary pump, gear driven by the camshaft at camshaft speed. It injects a precisely metered amount of fuel to each cylinder at the proper time. The pump is mounted on top of the engine and provides necessary timing advance under all operating conditions.
High pressure fuel lines (6 or 8) carry fuel from pump to an injection nozzle in each cylinder. All lines are exactly the same length to insure that there is no variance in timing. Engine RPM is controlled by a rotary fuel metering valve. As accelerator pedal is pushed down, throttle cable opens metering valve to allow increased fuel delivery. A built-in low pressure transfer pump delivers fuel to main injection pump.
A fuel filter is located between the fuel supply pump (mounted on side of engine block) and the fuel injection pump. Any excess fuel is returned to tank by a fuel return system. An optional diesel fuel heater is available for cold weather operation.
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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.