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Jeff Myers
Jeff Myers, RV Mechanic
Category: RV
Satisfied Customers: 198
Experience:  Owner of an RV Repair Facility for 9 years. 12VDC and 120VAC, ALL Appliances, Any and ALL problems!
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Diplomat: chassis..went dead..cummins 400 hp..wont start

Customer Question

i have a monaco diplomat chassis batteries went dead. cummins 400 hp tried to charge them and the engine would not quite turn over.   now new batteries and turns over won't start. do I need to try to prime engine. how do I do this ??? sounds like its flooded
Submitted: 6 years ago.
Category: RV
Expert:  Jeff Myers replied 6 years ago.
HelloCustomer My name is Jeff. Let's see if we can get you started!!!

Here is the prime procedure recommended by Cummins for your engine:

- Bump starter, allow fuel recirculation pump to run for 30 sec.; repeat 6 times, then crank for no more than 30 seconds. You may have to repeat this several times.

If you do not hear the recirculation pump, you may have a blown fuse, especially due to the fact that you had low batteries. One way to check and see if you are getting fuel to the engine is to have someone crank the motor and you crack a fuel injection line to see if fuel is coming out. If there is none, you have a supply problem, if there is, you have an ignition problem.

Check your fuses first. Your owners manual should tell you where the fuses for these parts are. Another easy thing to look at is if the tail pipe is smoking when you crank the motor. If the engine is getting fuel but not starting, you will get a bluish/black smoke at the tailpipe. If there is no smoke, then you have no fuel.

I hope this helps, if you have any further questions, then please do not hesitate to ask!!! I am always happy to help.

Regards XXXXX XXXXX luck,

Jeff Myers
Customer: replied 6 years ago.
when you say bump starter, i do not know what this means. how do i let the fuel recirculation pump to run.
Expert:  Jeff Myers replied 6 years ago.
Good morning,

Bumping the starter means just turning the engine over for a second. Don't hold the key in the start position for more than a second. The fuel recirculation pump should come on when the key is in the run position (turned forward to "On" but not "start").

Try this and let me know. Another way to do this is to remove the fuel filters and check if they are full. If not, fill them with diesel fuel or Automatic Transmission Fluid (helps to prime the system) and then try to start the engine.

Hope to hear from you soon,


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