﻿GET_GEVOMechL2_04_01_01_10 - ANIMATION Screen
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The high-pressure (HP) pumps are piston-type pumps that are driven from the camshaft at each power assembly.

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These pumps take fuel from the low-pressure supply header, pressurize it up to 23,000 psi, and send it to the injectors through the high-pressure fuel lines.

3
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The ECU governs the timing and amount of fuel delivered by each HP pump by opening and closing a solenoid located on the pump.

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When an HP pump is not pressurizing the fuel for the injection process, the solenoid on the HP pump is open.

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This allows the fuel from the low-pressure supply header to pass through the HP pump to the low-pressure return header.

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The return header runs parallel and under the low-pressure supply header to a regulating valve.

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The regulating valve is normally set to 90 psi with the engine at low idle.

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It provides backpressure in the low-pressure fuel lines to the HP pumps.

9
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A certain amount of pressure or restriction ensures sufficient filling of the HP pumps and helps prevent cavitation or loss of suction in the HP pumps.

10
00:01:04,583 --> 00:01:08,667
Fuel from the regulating valve drains back to the fuel tank.

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In addition, two gravity drain headers are located on each side of the engine.

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A small amount of fuel flows through each HP pump to lubricate and cool its internal parts.

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This fuel then drains through the drain header back to the fuel tank.

