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Ram Head
Ram Head, Dodge Technician
Category: Dodge
Satisfied Customers: 96
Experience:  ASE Certified. Daimler Chrysler certified. Current diesel tech at Dodge dealership. Diesel certified
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Cummins 5.9L. wont start. engine turns over.

Resolved Question:

cummins 5.9L. won't start. engine turns over. won't start. Sometimes starts then immediately dies. thought I had bad fuel. replaced fuel filter. added sea foam to fuel filter housing and to fuel tank. It started, ran around the block several times. stopped it and it started right back. I let it sit for couple of hours and the problem started all over agian. This time I even tried spraying starter fluid & wd40 to intake. tried to start, but didn't. If I could get it started I can run the bad fuel out. Any suggestions?
Submitted: 8 years ago.
Category: Dodge
Expert:  Ram Head replied 8 years ago.

Hello there.

It will help in the diagnostic process to know the following:

What year is vehicle?

Automatic or manual transmission?

Approximate mileage?

Has the check engine light come on? If so, what is the dtc?

What has been done to the vehicle so far?

All this will be helpful. Thank you.

Customer: replied 8 years ago.

2007 w/ 6 speed manual trans. 220,000. I drive hot shot. no check engine light on.


Refer back to question. That's what I've done. It just won't start and stay running!

Expert:  Ram Head replied 8 years ago.


The first thing I would do is run the Cummins diesel diagnostic fuel test on vehicle.

Running these tests will test transfer/lift pump flow across fuel filter, CP3 pump return flow, pressure limiting valve for leakage, and injector return flow.

These tests require special test fittings to install inline in fuel system and also require a scan tool to overide fuel pressure to boost psi to max. These tests will best to have done a Dodge or Cummins dealer.

In doing these tests they will determine if your transfer pump has the correct flow.

They will be able to verify fuel quality and determine if there is fuel contamination.

Testing the CP3 pump to verify it can actual pump the desired volume of fuel to rail.

Test the limiting valve to verify it is not leaking so fuel system can build proper psi for operation.

Test for excessive injector return flow which may be caused by leaking high pressure connector tubes at the injector socket, or internally damaged or restricted injectors.

Also, they will be able to check the engine controller for software level, as there have been many updates to software for driveability concerns.

THis is where I would start. It sounds like a fuel issue to me, and this will narrow down the concern the quickest way.

Hopefully this information is helpful. Thanks and good luck!

Customer: replied 8 years ago.

I was trying to avoid going to dealership. Any suggestions on getting it to start?

Expert:  Ram Head replied 8 years ago.

You may want to check your fuel quality yourself.

Drain the fuel filter at the fuel water seperator drain.

If you leave drain open and bump starter key, you will get fuel out of this drain. Verify that it is diesel and has no water contamination. If it smells like it has gas, put some fuel in a styrofoam cup and see if the cup melts. If it does, you have gasoline in the diesel. If not, then there is no gasoline. Let it seperate out in the cup and verify if there is water in fuel.

Other than checking fuel quality, there is not alot you will do to get it started. IF starter fluid is not working then you will more than likely be out of luck.

Be careful on the amounts of fluid you use to start vehicle and make sure intake grid heaters are not heating while using this fluid. Engine damage from over rev and extreme combustion buildup in a single cylinder will damage engine.

Sorry for the bad news. Good luck!

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