1994-1998 12 valve Cummins Engine Troubleshooting

Thursday, might 29, 2014 12:18:26 afternoon America/North_Dakota/Center


94-98 Fuel device troubleshooting

Engine won’t start:

Bleed the air out of the system

If girlfriend are starting your Cummins because that the an initial time, it is forced to “bleed” the air out of the injector present by loosening the injector heat nut just sufficient to allow fuel and air come escape the heat while you space cranking the engine. It is usually required to execute at the very least 3 injector lines. Tightening the line nut while you room still cranking the engine is the finest way. This is additionally a great way to verify the the injector pump’s shut under solenoid is enabling fuel to the injector. If your supply fuel line is loose, it is feasible to attract air into the fuel mechanism at the point, therefore if you doubt you are not gaining rid the the air in the system inspect your supply heat connections. This engines have to have between 18-30 psi or an ext of lift pump fuel pressure.

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Good supply pressure/fuel at injector

If you have actually fuel in ~ the injector, great fuel it is provided pressure, and you are fairly certain you have no more air in the system, you may have actually a weak injector pump or untrue injector pump timing. Friend may especially suspect this sort of problem if you have actually never heard the engine operation before, or you changed the injector pump.

Good supply pressure/no fuel at injector

If you have no fuel at the injector, yet you have great fuel pressure, then your shut under solenoid is not functioning properly. The shut under solenoid lifts the closeup of the door down lever on the injector pump to permit the engine come run. Start only power elevator the solenoid, and crucial on power holds it in the up position.

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Poor it is provided pressure

If girlfriend have bad supply pressure, inspect the overflow valve (shown inside the red circle in the photo below). This is a one-of-a-kind banjo bolt through a spring and ball inside that regulates the fuel push inside the injector pump. The is located in between the engine and the injector pump. take it the valve out and shake it. If the feather is damaged it will rattle. If the looks favor this one, you can take that apart and include or remove shims to readjust the pressure. Us don’t recommend pressures better than 60 psi. If over there is naught wrong with the overflow valve, climate you may have a lift pump problem- or a limit or an wait leak in your supply line in between the elevator pump and the tank.