The Cummins PT fuel system (fig. 5-28) is exclusive to Cummins diesel engines; PT stands for “Pressure – Time”. It uses injectors that meter and injects the fuel with this metering based on a pressure-time principle. A gear-driven positive displacement low-pressure fuel pump naturally supplies fuel pressure.
How does a Cummins PT fuel system work?
In the fuel pump, fuel flows through the governor to the throttle shaft. At idle speed, fuel flows through the idle port in the governor barrel, past the throttle shaft. To operate above idle speed, fuel flows through the main governor barrel port to the throttling hole in the shaft.
What is PT pump?
Pressure-time (PT) gear pump. on a pressure-time principle. … A flyball type mechanical governor controls fuel pressure and engine torque throughout the entire operating range. It also controls the idling speed of the engine and prevents engine overspeeding in the high- speed range.
How do I turn up my Cummins PT pump?
The quick and dirty way for more fuel on a PT pump is drill out the plug in the throttle shaft and turn the slotted screw out 1/4 to 1/2 a turn. This will not increase rpm, only fuel rate. To increase rpm you must shim the gov.
How do you bleed a Cummins PT pump?
To bleed the system just fill the filter and crank the engine over til it starts. To adjust the crossheads (the links between valves) press down on the lever, turn the screw til it just makes contact then turn an additional 1/4 turn and tighten nut. If you adjust the crossheads you will need to readjust the valves.
How does a PT injector work?
The injector injects a finely atomized fuel spray into the combustion chamber at spray-in-pressures exceeding 20,000 psi. A low-pressure common-rail system is used, with the pressure being developed in a gear-type pump. This eliminates the need for high-pressure fuel lines running from the fuel pump to each injector.
What is an aneroid valve?
The aneroid comprises valve means connected in the rail and operable to adjust the fuel pressure in the rail, the valve means including a movable member which is movable to adjust the fuel flow area through the rail and thereby adjust the fuel pressure downstream of the aneroid.
How many HP is a 444 Cummins?
1989 Cummins NTC444 Engine
|Horse Power||444 HP|
|Part Number||CPL 1280|
How much horsepower does a 855 Cummins have?
Cummins 855 Big Cam History and Specs
|Cummins 855 Specs||Engine Data|
|Max Horsepower||605 HP @ 1800 RPM|
|Max Torque Ratio||1,118 ft-lbs @1800 RPM|
|Governed Speed||1800 RPM|
How do you adjust the idle on a Cummins PT pump?
Adjust the idle speed. Turn the tool clockwise to increase the idle speed and counterclockwise to decrease the idle speed.
How do you start a Cummins that ran out of fuel?
Prime the fuel system by turning the ignition on (Run position) for 30 seconds, but do not start the engine. This allows the pump to prime the system. Turn the ignition off, and then crank it for 15 seconds. If it does not start, repeat the first task and this one until it starts (cycle the key).
How do you prime a 2nd Gen Cummins?
How to Prime a Cummins 5.9 Injector Pump
- Get into the driver’s seat of the vehicle.
- Turn the key to the “On” position and listen for the mechanical pump in the fuel tank to engage. The pump will run for about 20 seconds.
- Turn the key enough to engage the starter. …
- Repeat Step 3 four to five times to allow the fuel line to pressurize.